The ABI is settling on "similar" for this rule.

gcc/cp/ChangeLog:

	* class.cc (check_subobject_offset): Use similar_type_p.

Consider those VLS patterns are the same VLA patterns.
Now extend VI -> V_VLSI and VF -> V_VLSF.
Then remove the redundant codes of VLS patterns.

gcc/ChangeLog:

	* config/riscv/autovec-vls.md (<optab><mode>3): Deleted.
	(copysign<mode>3): Ditto.
	(xorsign<mode>3): Ditto.
	(<optab><mode>2): Ditto.
	* config/riscv/autovec.md: Extend VLS modes.

For "get_global_range_query" SSA_NAME_RANGE_INFO can be queried.
For "get_range_query", it could get more context-aware range info.
And look at the implementation of "get_range_query",  it returns
global range if no local fun info.

ATTRIBUTE_RETURNS_NONNULL inline range_query *
get_range_query (const struct function *fun)
{
  return (fun && fun->x_range_query) ? fun->x_range_query : &global_ranges;
}

So, using "get_range_query" would cover more case.
For example, the test case of "pr111303.c".

	PR middle-end/111303

gcc/ChangeLog:

	* match.pd ((t * 2) / 2): Update pattern.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr111303.c: New test.

So the xfail was there because at one point the difference
from having logical-op-non-short-circuit set to 1 or 0 made a
difference in being able to optimizing a conditional way.
This has not been true for over 10 years in this case so
instead of keeping on adding to the xfail list, removing it
is the right thing to do.

Committed as obvious after a test on x86_64-linux-gnu.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/20040204-1.c: Remove xfail.

For rs6000 target we dont need zero_extend after vctzlsbb as vctzlsbb
already zero extend.

2023-09-17  Ajit Kumar Agarwal  <aagarwa1@linux.ibm.com>

gcc/ChangeLog:

	* config/rs6000/vsx.md (*vctzlsbb_zext_<mode>): New define_insn.

gcc/testsuite/ChangeLog:

	* g++.target/powerpc/altivec-19.C: New testcase.

This patch fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111391

	PR target/111391

gcc/ChangeLog:

	* config/riscv/autovec.md (@vec_extract<mode><vel>): Remove @.
	(vec_extract<mode><vel>): Ditto.
	* config/riscv/riscv-vsetvl.cc (emit_vsetvl_insn): Fix bug.
	(pass_vsetvl::local_eliminate_vsetvl_insn): Fix bug.
	* config/riscv/riscv.cc (riscv_legitimize_move): Expand VLS mode to scalar mode move.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/partial/slp-9.c: Adapt test.
	* gcc.target/riscv/rvv/autovec/pr111391-1.c: New test.
	* gcc.target/riscv/rvv/autovec/pr111391-2.c: New test.

This is in parity with the LLVM commit a64b3e92c7cb ("[RISCV] Re-define
sha256, Zksed, and Zksh intrinsics to use i32 types.").

SHA-256, SM3 and SM4 instructions operate on 32-bit integers and upper
32-bits have no effects on RV64 (the output is sign-extended from the
original 32-bit value).  In that sense, making those intrinsics only
operate on uint32_t is much more natural than XLEN-bits wide integers.

This commit reforms instructions and expansions based on 32-bit
instruction handling on RV64 (such as ADDW).

Before:
   riscv_<op>_si: For RV32, fully operate on uint32_t
   riscv_<op>_di: For RV64, fully operate on uint64_t
After:
  *riscv_<op>_si: For RV32, fully operate on uint32_t
   riscv_<op>_di_extended:
                  For RV64.  Input is uint32_t and output is int64_t,
                  sign-extended from the int32_t result
                  (represents a part of <op> behavior).
   riscv_<op>_si: Common (fully operate on uint32_t).
                  On RV32, "expands" to *riscv_<op>_si.
                  On RV64, initially expands to riscv_<op>_di_extended *and*
                  extracts lower 32-bits from the int64_t result.

It also refines definitions of SHA-256, SM3 and SM4 intrinsics.

gcc/ChangeLog:

	* config/riscv/crypto.md (riscv_sha256sig0_<mode>,
	riscv_sha256sig1_<mode>, riscv_sha256sum0_<mode>,
	riscv_sha256sum1_<mode>, riscv_sm3p0_<mode>, riscv_sm3p1_<mode>,
	riscv_sm4ed_<mode>, riscv_sm4ks_<mode>): Remove and replace with
	new insn/expansions.
	(SHA256_OP, SM3_OP, SM4_OP): New iterators.
	(sha256_op, sm3_op, sm4_op): New attributes for iteration.
	(*riscv_<sha256_op>_si): New raw instruction for RV32.
	(*riscv_<sm3_op>_si): Ditto.
	(*riscv_<sm4_op>_si): Ditto.
	(riscv_<sha256_op>_di_extended): New base instruction for RV64.
	(riscv_<sm3_op>_di_extended): Ditto.
	(riscv_<sm4_op>_di_extended): Ditto.
	(riscv_<sha256_op>_si): New common instruction expansion.
	(riscv_<sm3_op>_si): Ditto.
	(riscv_<sm4_op>_si): Ditto.
	* config/riscv/riscv-builtins.cc: Add availability "crypto_zknh",
	"crypto_zksh" and "crypto_zksed".  Remove availability
	"crypto_zksh{32,64}" and "crypto_zksed{32,64}".
	* config/riscv/riscv-ftypes.def: Remove unused function type.
	* config/riscv/riscv-scalar-crypto.def: Make SHA-256, SM3 and SM4
	intrinsics to operate on uint32_t.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/zknh-sha256.c: Moved to...
	* gcc.target/riscv/zknh-sha256-64.c: ...here.  Test RV64.
	* gcc.target/riscv/zknh-sha256-32.c: New test for RV32.
	* gcc.target/riscv/zksh64.c: Change the type.
	* gcc.target/riscv/zksed64.c: Ditto.

For bit manipulation operations, input(s) and the manipulated output are
better to be unsigned like other target-independent builtins like
__builtin_bswap32 and __builtin_popcount.

Although this is not completely compatible as before (as the type changes),
most code will run normally, even without warnings (with -Wall -Wextra).

To make consistent to the LLVM commit 599421ae36c3 ("[RISCV] Use unsigned
instead of signed types for Zk* and Zb* builtins."), round numbers and
shift amount on the scalar crypto instructions are also changed
to unsigned.

gcc/ChangeLog:

	* config/riscv/riscv-builtins.cc (RISCV_ATYPE_UQI): New for
	uint8_t.  (RISCV_ATYPE_UHI): New for uint16_t.
	(RISCV_ATYPE_QI, RISCV_ATYPE_HI, RISCV_ATYPE_SI, RISCV_ATYPE_DI):
	Removed as no longer used.
	(RISCV_ATYPE_UDI): New for uint64_t.
	* config/riscv/riscv-cmo.def: Make types unsigned for not working
	"zicbop_cbo_prefetchi" and working bit manipulation clmul builtin
	argument/return types.
	* config/riscv/riscv-ftypes.def: Make bit manipulation, round
	number and shift amount types unsigned.
	* config/riscv/riscv-scalar-crypto.def: Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/zbc32.c: Make signed type to unsigned.
	* gcc.target/riscv/zbc64.c: Ditto.
	* gcc.target/riscv/zbkb32.c: Ditto.
	* gcc.target/riscv/zbkb64.c: Ditto.
	* gcc.target/riscv/zbkc32.c: Ditto.
	* gcc.target/riscv/zbkc64.c: Ditto.
	* gcc.target/riscv/zbkx32.c: Ditto.
	* gcc.target/riscv/zbkx64.c: Ditto.
	* gcc.target/riscv/zknd32.c: Ditto.
	* gcc.target/riscv/zknd64.c: Ditto.
	* gcc.target/riscv/zkne32.c: Ditto.
	* gcc.target/riscv/zkne64.c: Ditto.
	* gcc.target/riscv/zknh-sha256.c: Ditto.
	* gcc.target/riscv/zknh-sha512-32.c: Ditto.
	* gcc.target/riscv/zknh-sha512-64.c: Ditto.
	* gcc.target/riscv/zksed32.c: Ditto.
	* gcc.target/riscv/zksed64.c: Ditto.
	* gcc.target/riscv/zksh32.c: Ditto.
	* gcc.target/riscv/zksh64.c: Ditto.

This patch would like to allow the VLS mode autovec for the
floating-point binary operation SGNJX.

Give sample code as below:

void
test (float * restrict out, float * restrict in1, float * restrict in2)
{
  for (int i = 0; i < 128; i++)
    out[i] = in1[i] * copysignf (1.0, in2[i]);
}

Before this patch:
test:
  li      a5,128
  vsetvli zero,a5,e32,m1,ta,ma
  vle32.v v2,0(a1)
  lui     a4,%hi(.LC0)
  flw     fa5,%lo(.LC0)(a4)
  vfmv.v.f        v1,fa5
  vle32.v v3,0(a2)
  vfsgnj.vv       v1,v1,v3
  vfmul.vv        v1,v1,v2
  vse32.v v1,0(a0)
  ret

After this patch:
test:
  li      a5,128
  vsetvli zero,a5,e32,m1,ta,ma
  vle32.v v1,0(a1)
  vle32.v v2,0(a2)
  vfsgnjx.vv      v1,v1,v2
  vse32.v v1,0(a0)
  ret

This SGNJX autovec acts on function call copysignf/copysignf
in math.h too. And it depends on the option -ffast-math.

gcc/ChangeLog:

	* config/riscv/autovec-vls.md (xorsign<mode>3): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/vls/def.h: New macro.
	* gcc.target/riscv/rvv/autovec/vls/floating-point-sgnjx-1.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/floating-point-sgnjx-2.c: New test.

Signed-off-by: Pan Li <pan2.li@intel.com>

We can remove { dg-require-effective-target pthread } and allow these
tests non-pthread targets and conditionally adding -pthread only for
pthread targets.

Also remove the { dg-options "-std=gnu++20" } that is no longer needed.

libstdc++-v3/ChangeLog:

	* testsuite/29_atomics/atomic_ref/wait_notify.cc: Do not
	restrict to pthreads targets.
	* testsuite/30_threads/jthread/3.cc: Likewise.
	* testsuite/30_threads/semaphore/100806.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire_for.cc: Likewise.
	* testsuite/30_threads/semaphore/try_acquire_posix.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/18_support/coroutines/95917.cc: Remove dg-options
	-std=gnu++2a.
	* testsuite/18_support/coroutines/hash.cc: Likewise.
	* testsuite/18_support/coroutines/lwg3460.cc: Likewise.
	* testsuite/18_support/destroying_delete.cc: Likewise.
	* testsuite/18_support/source_location/1.cc: Likewise.
	* testsuite/18_support/source_location/consteval.cc: Likewise.
	* testsuite/18_support/source_location/version.cc: Likewise.
	* testsuite/19_diagnostics/error_category/operators/three_way.cc:
	Likewise.
	* testsuite/19_diagnostics/error_code/operators/three_way.cc:
	Likewise.
	* testsuite/19_diagnostics/error_condition/operators/three_way.cc:
	Likewise.
	* testsuite/19_diagnostics/stacktrace/output.cc: Likewise.
	* testsuite/26_numerics/adjacent_difference/lwg2055.cc:
	Likewise.
	* testsuite/26_numerics/bit/bit.count/countl_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countr_one.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countr_zero.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/popcount.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/bit_ceil.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/has_single_bit.cc:
	Likewise.
	* testsuite/28_regex/iterators/regex_iterator/lwg3719.cc:
	Likewise.
	* testsuite/28_regex/iterators/regex_token_iterator/lwg3719.cc:
	Likewise.
	* testsuite/28_regex/sub_match/compare_c++20.cc: Likewise.
	* testsuite/experimental/filesystem/iterators/106201.cc:
	Likewise.
	* testsuite/experimental/scopeguard/exit.cc: Likewise.
	* testsuite/experimental/scopeguard/uniqueres.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/30_threads/barrier/1.cc: Remove dg-options
	-std=gnu++20.
	* testsuite/30_threads/barrier/2.cc: Likewise.
	* testsuite/30_threads/barrier/arrive.cc: Likewise.
	* testsuite/30_threads/barrier/arrive_and_drop.cc: Likewise.
	* testsuite/30_threads/barrier/arrive_and_wait.cc: Likewise.
	* testsuite/30_threads/barrier/completion.cc: Likewise.
	* testsuite/30_threads/condition_variable/members/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/condition_variable_any/members/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/condition_variable_any/stop_token/1.cc:
	Likewise.
	* testsuite/30_threads/condition_variable_any/stop_token/2.cc:
	Likewise.
	* testsuite/30_threads/future/members/clock_neg.cc: Likewise.
	* testsuite/30_threads/headers/stop_token/synopsis.cc: Likewise.
	* testsuite/30_threads/headers/thread/types_std_c++20.cc:
	Likewise.
	* testsuite/30_threads/jthread/1.cc: Likewise.
	* testsuite/30_threads/jthread/100612.cc: Likewise.
	* testsuite/30_threads/jthread/95989.cc: Likewise.
	* testsuite/30_threads/jthread/jthread.cc: Likewise.
	* testsuite/30_threads/jthread/version.cc: Likewise.
	* testsuite/30_threads/latch/1.cc: Likewise.
	* testsuite/30_threads/latch/2.cc: Likewise.
	* testsuite/30_threads/latch/3.cc: Likewise.
	* testsuite/30_threads/recursive_timed_mutex/try_lock_until/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/semaphore/1.cc: Likewise.
	* testsuite/30_threads/semaphore/2.cc: Likewise.
	* testsuite/30_threads/semaphore/least_max_value_neg.cc:
	Likewise.
	* testsuite/30_threads/semaphore/try_acquire_until.cc: Likewise.
	* testsuite/30_threads/shared_future/members/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/shared_lock/locking/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/shared_timed_mutex/try_lock_until/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/stop_token/1.cc: Likewise.
	* testsuite/30_threads/stop_token/2.cc: Likewise.
	* testsuite/30_threads/stop_token/stop_callback.cc: Likewise.
	* testsuite/30_threads/stop_token/stop_callback/deadlock.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_callback/destructible_neg.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_callback/invocable_neg.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_callback/invoke.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_source.cc: Likewise.
	* testsuite/30_threads/stop_token/stop_source/assign.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_token.cc: Likewise.
	* testsuite/30_threads/stop_token/stop_token/stop_possible.cc:
	Likewise.
	* testsuite/30_threads/thread/id/operators_c++20.cc: Likewise.
	* testsuite/30_threads/timed_mutex/try_lock_until/clock_neg.cc:
	Likewise.
	* testsuite/30_threads/unique_lock/locking/clock_neg.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/27_io/basic_istream/extractors_character/char/lwg2499.cc:
	Remove dg-options -std=gnu++2a.
	* testsuite/27_io/basic_istream/extractors_character/char/lwg2499_neg.cc:
	Likewise.
	* testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499.cc:
	Likewise.
	* testsuite/27_io/basic_istream/extractors_character/wchar_t/lwg2499_neg.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/cons/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/str/char/2.cc: Likewise.
	* testsuite/27_io/basic_istringstream/str/wchar_t/2.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostream/emit/1.cc: Likewise.
	* testsuite/27_io/basic_ostream/inserters_character/char/deleted.cc:
	Likewise.
	* testsuite/27_io/basic_ostream/inserters_character/wchar_t/deleted.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/cons/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/str/char/3.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/str/wchar_t/3.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringbuf/cons/char/2.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/cons/wchar_t/2.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/str/char/4.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/str/wchar_t/4.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/view/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/cons/char/97719.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/cons/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/str/char/5.cc: Likewise.
	* testsuite/27_io/basic_stringstream/str/wchar_t/5.cc.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_syncbuf/1.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/2.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/basic_ops/1.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/requirements/types.cc: Likewise.
	* testsuite/27_io/basic_syncbuf/sync_ops/1.cc: Likewise.
	* testsuite/27_io/basic_syncstream/1.cc: Likewise.
	* testsuite/27_io/basic_syncstream/2.cc: Likewise.
	* testsuite/27_io/basic_syncstream/basic_ops/1.cc: Likewise.
	* testsuite/27_io/basic_syncstream/requirements/types.cc:
	Likewise.
	* testsuite/27_io/filesystem/iterators/106201.cc: Likewise.
	* testsuite/27_io/filesystem/iterators/lwg3719.cc: Likewise.
	* testsuite/27_io/filesystem/path/factory/u8path-depr.cc:
	Likewise.
	* testsuite/27_io/filesystem/path/nonmember/cmp_c++20.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/26_numerics/accumulate/constexpr.cc: Remove
	dg-options -std=gnu++2a.
	* testsuite/26_numerics/accumulate/lwg2055.cc: Likewise.
	* testsuite/26_numerics/adjacent_difference/constexpr.cc:
	Likewise.
	* testsuite/26_numerics/bit/bit.cast/105027.cc: Likewise.
	* testsuite/26_numerics/bit/bit.cast/bit_cast.cc: Likewise.
	* testsuite/26_numerics/bit/bit.cast/version.cc: Likewise.
	* testsuite/26_numerics/bit/bit.count/countl_one.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/bit_ceil_neg.cc:
	Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/bit_floor.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/bit_width.cc: Likewise.
	* testsuite/26_numerics/bit/bit.pow.two/lwg3656.cc: Likewise.
	* testsuite/26_numerics/bit/bit.rotate/rotl.cc: Likewise.
	* testsuite/26_numerics/bit/bit.rotate/rotr.cc: Likewise.
	* testsuite/26_numerics/bit/header-2.cc: Likewise.
	* testsuite/26_numerics/bit/header.cc: Likewise.
	* testsuite/26_numerics/complex/1.cc: Likewise.
	* testsuite/26_numerics/complex/2.cc: Likewise.
	* testsuite/26_numerics/complex/comparison_operators/more_constexpr.cc:
	Likewise.
	* testsuite/26_numerics/complex/operators/more_constexpr.cc:
	Likewise.
	* testsuite/26_numerics/complex/requirements/more_constexpr.cc:
	Likewise.
	* testsuite/26_numerics/complex/value_operations/more_constexpr.cc:
	Likewise.
	* testsuite/26_numerics/endian/1.cc: Likewise.
	* testsuite/26_numerics/endian/2.cc: Likewise.
	* testsuite/26_numerics/endian/3.cc: Likewise.
	* testsuite/26_numerics/exclusive_scan/constexpr.cc: Likewise.
	* testsuite/26_numerics/inclusive_scan/constexpr.cc: Likewise.
	* testsuite/26_numerics/inner_product/constexpr.cc: Likewise.
	* testsuite/26_numerics/inner_product/lwg2055.cc: Likewise.
	* testsuite/26_numerics/iota/constexpr.cc: Likewise.
	* testsuite/26_numerics/lerp/1.cc: Likewise.
	* testsuite/26_numerics/lerp/constexpr.cc: Likewise.
	* testsuite/26_numerics/lerp/version.cc: Likewise.
	* testsuite/26_numerics/midpoint/floating.cc: Likewise.
	* testsuite/26_numerics/midpoint/integral.cc: Likewise.
	* testsuite/26_numerics/midpoint/pointer.cc: Likewise.
	* testsuite/26_numerics/midpoint/pointer_neg.cc: Likewise.
	* testsuite/26_numerics/midpoint/version.cc: Likewise.
	* testsuite/26_numerics/numbers/1.cc: Likewise.
	* testsuite/26_numerics/numbers/2.cc: Likewise.
	* testsuite/26_numerics/numbers/3.cc: Likewise.
	* testsuite/26_numerics/numbers/float128.cc: Likewise.
	* testsuite/26_numerics/numbers/nonfloat_neg.cc: Likewise.
	* testsuite/26_numerics/partial_sum/constexpr.cc: Likewise.
	* testsuite/26_numerics/partial_sum/lwg2055.cc: Likewise.
	* testsuite/26_numerics/random/concept.cc: Likewise.
	* testsuite/26_numerics/reduce/constexpr.cc: Likewise.
	* testsuite/26_numerics/slice/compare.cc: Likewise.
	* testsuite/26_numerics/transform_exclusive_scan/constexpr.cc:
	Likewise.
	* testsuite/26_numerics/transform_inclusive_scan/constexpr.cc:
	Likewise.
	* testsuite/26_numerics/transform_reduce/constexpr.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/24_iterators/aliases.cc: Remove dg-options
	-std=gnu++2a.
	* testsuite/24_iterators/associated_types/incrementable.traits.cc:
	Likewise.
	* testsuite/24_iterators/associated_types/iterator.traits.cc:
	Likewise.
	* testsuite/24_iterators/associated_types/readable.traits.cc:
	Likewise.
	* testsuite/24_iterators/back_insert_iterator/constexpr.cc:
	Likewise.
	* testsuite/24_iterators/back_insert_iterator/pr93884.cc:
	Likewise.
	* testsuite/24_iterators/bidirectional/concept.cc: Likewise.
	* testsuite/24_iterators/common_iterator/1.cc: Likewise.
	* testsuite/24_iterators/common_iterator/100823.cc: Likewise.
	* testsuite/24_iterators/common_iterator/2.cc: Likewise.
	* testsuite/24_iterators/contiguous/concept.cc: Likewise.
	* testsuite/24_iterators/contiguous/tag.cc: Likewise.
	* testsuite/24_iterators/counted_iterator/1.cc: Likewise.
	* testsuite/24_iterators/counted_iterator/lwg3389.cc: Likewise.
	* testsuite/24_iterators/counted_iterator/lwg3643.cc: Likewise.
	* testsuite/24_iterators/customization_points/92894.cc:
	Likewise.
	* testsuite/24_iterators/customization_points/iter_move.cc:
	Likewise.
	* testsuite/24_iterators/customization_points/iter_swap.cc:
	Likewise.
	* testsuite/24_iterators/customization_points/lwg3420.cc:
	Likewise.
	* testsuite/24_iterators/forward/concept.cc: Likewise.
	* testsuite/24_iterators/front_insert_iterator/constexpr.cc:
	Likewise.
	* testsuite/24_iterators/front_insert_iterator/pr93884.cc:
	Likewise.
	* testsuite/24_iterators/headers/iterator/synopsis_c++20.cc:
	Likewise.
	* testsuite/24_iterators/indirect_callable/92894.cc: Likewise.
	* testsuite/24_iterators/indirect_callable/projected-adl.cc:
	Likewise.
	* testsuite/24_iterators/indirect_callable/projected.cc:
	Likewise.
	* testsuite/24_iterators/input/concept.cc: Likewise.
	* testsuite/24_iterators/insert_iterator/constexpr.cc: Likewise.
	* testsuite/24_iterators/istream_iterator/cons/sentinel.cc:
	Likewise.
	* testsuite/24_iterators/istream_iterator/sentinel.cc: Likewise.
	* testsuite/24_iterators/istreambuf_iterator/cons/sentinel.cc:
	Likewise.
	* testsuite/24_iterators/istreambuf_iterator/sentinel.cc:
	Likewise.
	* testsuite/24_iterators/move_iterator/cust.cc: Likewise.
	* testsuite/24_iterators/move_iterator/dr3435.cc: Likewise.
	* testsuite/24_iterators/move_iterator/input_iterator.cc:
	Likewise.
	* testsuite/24_iterators/move_iterator/lwg3390.cc: Likewise.
	* testsuite/24_iterators/move_iterator/lwg3391.cc: Likewise.
	* testsuite/24_iterators/move_iterator/move_only.cc: Likewise.
	* testsuite/24_iterators/move_iterator/p2520r0.cc: Likewise.
	* testsuite/24_iterators/move_iterator/rel_ops_c++20.cc:
	Likewise.
	* testsuite/24_iterators/move_iterator/sentinel.cc: Likewise.
	* testsuite/24_iterators/normal_iterator/cmp_c++20.cc: Likewise.
	* testsuite/24_iterators/output/concept.cc: Likewise.
	* testsuite/24_iterators/random_access/concept.cc: Likewise.
	* testsuite/24_iterators/range_access/range_access_cpp20.cc:
	Likewise.
	* testsuite/24_iterators/range_access/range_access_cpp20_neg.cc:
	Likewise.
	* testsuite/24_iterators/range_operations/100768.cc: Likewise.
	* testsuite/24_iterators/range_operations/advance.cc: Likewise.
	* testsuite/24_iterators/range_operations/advance_overflow.cc:
	Likewise.
	* testsuite/24_iterators/range_operations/distance.cc: Likewise.
	* testsuite/24_iterators/range_operations/lwg3392.cc: Likewise.
	* testsuite/24_iterators/range_operations/next.cc: Likewise.
	* testsuite/24_iterators/range_operations/prev.cc: Likewise.
	* testsuite/24_iterators/reverse_iterator/cust.cc: Likewise.
	* testsuite/24_iterators/reverse_iterator/dr3435.cc: Likewise.
	* testsuite/24_iterators/reverse_iterator/rel_ops_c++20.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/23_containers/array/comparison_operators/96851.cc:
	Remove dg-options -std=gnu++2a.
	* testsuite/23_containers/array/comparison_operators/constexpr.cc:
	Likewise.
	* testsuite/23_containers/array/creation/1.cc: Likewise.
	* testsuite/23_containers/array/creation/110167.cc: Likewise.
	* testsuite/23_containers/array/creation/2.cc: Likewise.
	* testsuite/23_containers/array/creation/3_neg.cc: Likewise.
	* testsuite/23_containers/array/requirements/constexpr_fill.cc:
	Likewise.
	* testsuite/23_containers/array/requirements/constexpr_swap.cc:
	Likewise.
	* testsuite/23_containers/deque/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/deque/erasure.cc: Likewise.
	* testsuite/23_containers/deque/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/deque/operators/cmp_c++20.cc:
	Likewise.
	* testsuite/23_containers/forward_list/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/forward_list/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/forward_list/erasure.cc: Likewise.
	* testsuite/23_containers/forward_list/modifiers/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/forward_list/operations/remove_cxx20_return.cc:
	Likewise.
	* testsuite/23_containers/forward_list/operations/unique_cxx20_return.cc:
	Likewise.
	* testsuite/23_containers/list/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/list/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/list/erasure.cc: Likewise.
	* testsuite/23_containers/list/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/list/operations/remove_cxx20_return.cc:
	Likewise.
	* testsuite/23_containers/list/operations/unique_cxx20_return.cc:
	Likewise.
	* testsuite/23_containers/map/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/map/erasure.cc: Likewise.
	* testsuite/23_containers/map/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/map/operations/contains.cc: Likewise.
	* testsuite/23_containers/map/operators/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/multimap/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/multimap/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/multimap/operations/contains.cc:
	Likewise.
	* testsuite/23_containers/multimap/operators/cmp_c++20.cc:
	Likewise.
	* testsuite/23_containers/multiset/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/multiset/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/multiset/operations/contains.cc:
	Likewise.
	* testsuite/23_containers/multiset/operators/cmp_c++20.cc:
	Likewise.
	* testsuite/23_containers/priority_queue/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/queue/92878_92947.cc: Likewise.
	* testsuite/23_containers/queue/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/set/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/set/erasure.cc: Likewise.
	* testsuite/23_containers/set/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/set/operations/contains.cc: Likewise.
	* testsuite/23_containers/set/operators/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/span/1.cc: Likewise.
	* testsuite/23_containers/span/101411.cc: Likewise.
	* testsuite/23_containers/span/2.cc: Likewise.
	* testsuite/23_containers/span/deduction.cc: Likewise.
	* testsuite/23_containers/span/explicit.cc: Likewise.
	* testsuite/23_containers/span/layout_compat.cc: Likewise.
	* testsuite/23_containers/span/lwg3255.cc: Likewise.
	* testsuite/23_containers/span/nothrow_cons.cc: Likewise.
	* testsuite/23_containers/span/trivially_copyable.cc: Likewise.
	* testsuite/23_containers/stack/92878_92947.cc: Likewise.
	* testsuite/23_containers/stack/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/unordered_map/48101-3_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_map/erasure.cc: Likewise.
	* testsuite/23_containers/unordered_map/modifiers/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/unordered_map/operations/1.cc:
	Likewise.
	* testsuite/23_containers/unordered_map/operations/contains.cc:
	Likewise.
	* testsuite/23_containers/unordered_multimap/48101-3_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_multimap/modifiers/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/unordered_multimap/operations/1.cc:
	Likewise.
	* testsuite/23_containers/unordered_multimap/operations/contains.cc:
	Likewise.
	* testsuite/23_containers/unordered_multiset/48101-3_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_multiset/modifiers/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/unordered_multiset/operations/1.cc:
	Likewise.
	* testsuite/23_containers/unordered_multiset/operations/contains.cc:
	Likewise.
	* testsuite/23_containers/unordered_set/48101-3_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_set/erasure.cc: Likewise.
	* testsuite/23_containers/unordered_set/modifiers/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/unordered_set/operations/1.cc:
	Likewise.
	* testsuite/23_containers/unordered_set/operations/contains.cc:
	Likewise.
	* testsuite/23_containers/vector/48101-3_neg.cc: Likewise.
	* testsuite/23_containers/vector/bool/capacity/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/vector/bool/cons/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/element_access/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/iterator_c++20.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/modifiers/assign/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/modifiers/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/bool/modifiers/swap/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/capacity/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/cmp_c++20.cc: Likewise.
	* testsuite/23_containers/vector/cons/constexpr.cc: Likewise.
	* testsuite/23_containers/vector/data_access/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/element_access/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/erasure.cc: Likewise.
	* testsuite/23_containers/vector/modifiers/assign/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/modifiers/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/modifiers/emplace/92878_92947.cc:
	Likewise.
	* testsuite/23_containers/vector/modifiers/swap/constexpr.cc:
	Likewise.
	* testsuite/23_containers/vector/requirements/version.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/21_strings/basic_string/cons/char/105995.cc: Remove
	dg-options -std=gnu++20.
	* testsuite/21_strings/basic_string/cons/char/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string/cons/wchar_t/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string/erasure.cc: Likewise.
	* testsuite/21_strings/basic_string/hash/hash_char8_t.cc:
	Likewise.
	* testsuite/21_strings/basic_string/literals/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string/modifiers/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string/modifiers/swap/constexpr-wchar_t.cc:
	Likewise.
	* testsuite/21_strings/basic_string/modifiers/swap/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/ends_with/char.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/ends_with/nonnull.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/ends_with/wchar_t.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/starts_with/char.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/starts_with/nonnull.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/starts_with/wchar_t.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operators/char/cmp_c++20.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operators/wchar_t/cmp_c++20.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/cons/char/range.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/copy/char/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/copy/wchar_t/constexpr.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/ends_with/char.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/ends_with/nonnull.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/ends_with/wchar_t.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/starts_with/char.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/starts_with/nonnull.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operations/starts_with/wchar_t.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operators/char/cmp_c++20.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/operators/wchar_t/cmp_c++20.cc:
	Likewise.
	* testsuite/21_strings/basic_string_view/requirements/constexpr_iter.cc:
	Likewise.
	* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/allocator/105975.cc: Remove dg-options
	-std=gnu++2a.
	* testsuite/20_util/allocator/rebind_c++20.cc: Likewise.
	* testsuite/20_util/allocator/requirements/constexpr.cc:
	Likewise.
	* testsuite/20_util/allocator/requirements/typedefs_c++20.cc:
	Likewise.
	* testsuite/20_util/allocator_traits/header-2.cc: Likewise.
	* testsuite/20_util/allocator_traits/header.cc: Likewise.
	* testsuite/20_util/allocator_traits/members/92878_92947.cc:
	Likewise.
	* testsuite/20_util/any/assign/92878_92947.cc: Likewise.
	* testsuite/20_util/any/cons/92878_92947.cc: Likewise.
	* testsuite/20_util/assume_aligned/1.cc: Likewise.
	* testsuite/20_util/assume_aligned/2_neg.cc: Likewise.
	* testsuite/20_util/assume_aligned/3.cc: Likewise.
	* testsuite/20_util/assume_aligned/97132.cc: Likewise.
	* testsuite/20_util/bind/constexpr.cc: Likewise.
	* testsuite/20_util/bitset/operations/96303.cc: Likewise.
	* testsuite/20_util/common_reference/100894.cc: Likewise.
	* testsuite/20_util/common_reference/requirements/alias_decl.cc:
	Likewise.
	* testsuite/20_util/common_reference/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/common_reference/requirements/typedefs.cc:
	Likewise.
	* testsuite/20_util/duration/comparison_operators/three_way.cc:
	Likewise.
	* testsuite/20_util/exchange/constexpr.cc: Likewise.
	* testsuite/20_util/exchange/noexcept.cc: Likewise.
	* testsuite/20_util/from_chars/1_c++20_neg.cc: Likewise.
	* testsuite/20_util/from_chars/compare.cc: Likewise.
	* testsuite/20_util/function_objects/bind_front/1.cc: Likewise.
	* testsuite/20_util/function_objects/bind_front/107784.cc:
	Likewise.
	* testsuite/20_util/function_objects/bind_front/111327.cc:
	Likewise.
	* testsuite/20_util/function_objects/bind_front/2.cc: Likewise.
	* testsuite/20_util/function_objects/bind_front/97101.cc:
	Likewise.
	* testsuite/20_util/function_objects/bind_front/constexpr.cc:
	Likewise.
	* testsuite/20_util/function_objects/constexpr_searcher.cc:
	Likewise.
	* testsuite/20_util/function_objects/identity/1.cc: Likewise.
	* testsuite/20_util/function_objects/invoke/constexpr.cc:
	Likewise.
	* testsuite/20_util/function_objects/mem_fn/constexpr.cc:
	Likewise.
	* testsuite/20_util/function_objects/not_fn/constexpr.cc:
	Likewise.
	* testsuite/20_util/integer_comparisons/1.cc: Likewise.
	* testsuite/20_util/integer_comparisons/2.cc: Likewise.
	* testsuite/20_util/integer_comparisons/equal.cc: Likewise.
	* testsuite/20_util/integer_comparisons/equal_neg.cc: Likewise.
	* testsuite/20_util/integer_comparisons/greater.cc: Likewise.
	* testsuite/20_util/integer_comparisons/greater_equal.cc:
	Likewise.
	* testsuite/20_util/integer_comparisons/greater_equal_neg.cc:
	Likewise.
	* testsuite/20_util/integer_comparisons/greater_neg.cc:
	Likewise.
	* testsuite/20_util/integer_comparisons/in_range.cc: Likewise.
	* testsuite/20_util/integer_comparisons/in_range_neg.cc:
	Likewise.
	* testsuite/20_util/integer_comparisons/less.cc: Likewise.
	* testsuite/20_util/integer_comparisons/less_equal.cc: Likewise.
	* testsuite/20_util/integer_comparisons/less_equal_neg.cc:
	Likewise.
	* testsuite/20_util/integer_comparisons/less_neg.cc: Likewise.
	* testsuite/20_util/integer_comparisons/not_equal.cc: Likewise.
	* testsuite/20_util/integer_comparisons/not_equal_neg.cc:
	Likewise.
	* testsuite/20_util/is_bounded_array/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/is_bounded_array/requirements/typedefs.cc:
	Likewise.
	* testsuite/20_util/is_bounded_array/value.cc: Likewise.
	* testsuite/20_util/is_constant_evaluated/1.cc: Likewise.
	* testsuite/20_util/is_constant_evaluated/noexcept.cc: Likewise.
	* testsuite/20_util/is_constructible/92878_92947.cc: Likewise.
	* testsuite/20_util/is_layout_compatible/is_corresponding_member.cc:
	Likewise.
	* testsuite/20_util/is_layout_compatible/value.cc: Likewise.
	* testsuite/20_util/is_layout_compatible/version.cc: Likewise.
	* testsuite/20_util/is_nothrow_constructible/value_c++20.cc:
	Likewise.
	* testsuite/20_util/is_nothrow_convertible/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/is_nothrow_convertible/requirements/typedefs.cc:
	Likewise.
	* testsuite/20_util/is_nothrow_convertible/value.cc: Likewise.
	* testsuite/20_util/is_pod/deprecated-2a.cc: Likewise.
	* testsuite/20_util/is_pointer_interconvertible/value.cc:
	Likewise.
	* testsuite/20_util/is_pointer_interconvertible/version.cc:
	Likewise.
	* testsuite/20_util/is_pointer_interconvertible/with_class.cc:
	Likewise.
	* testsuite/20_util/is_unbounded_array/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/is_unbounded_array/requirements/typedefs.cc:
	Likewise.
	* testsuite/20_util/is_unbounded_array/value.cc: Likewise.
	* testsuite/20_util/optional/assignment/92878_92947.cc:
	Likewise.
	* testsuite/20_util/optional/cons/92878_92947.cc: Likewise.
	* testsuite/20_util/optional/constexpr/assign.cc: Likewise.
	* testsuite/20_util/optional/constexpr/cons/conv.cc: Likewise.
	* testsuite/20_util/optional/constexpr/modifiers.cc: Likewise.
	* testsuite/20_util/optional/constexpr/swap.cc: Likewise.
	* testsuite/20_util/optional/relops/96269.cc: Likewise.
	* testsuite/20_util/optional/relops/three_way.cc: Likewise.
	* testsuite/20_util/pair/comparison_operators/constexpr_c++20.cc:
	Likewise.
	* testsuite/20_util/pair/cons/92878_92947.cc: Likewise.
	* testsuite/20_util/pair/constexpr_assign.cc: Likewise.
	* testsuite/20_util/pair/constexpr_swap.cc: Likewise.
	* testsuite/20_util/pair/requirements/structural.cc: Likewise.
	* testsuite/20_util/pointer_traits/pointer_to_constexpr.cc:
	Likewise.
	* testsuite/20_util/polymorphic_allocator/allocate_object.cc:
	Likewise.
	* testsuite/20_util/polymorphic_allocator/construct_c++2a.cc:
	Likewise.
	* testsuite/20_util/polymorphic_allocator/lwg3237.cc: Likewise.
	* testsuite/20_util/reference_wrapper/constexpr.cc: Likewise.
	* testsuite/20_util/reference_wrapper/incomplete.cc: Likewise.
	* testsuite/20_util/remove_cvref/requirements/alias_decl.cc:
	Likewise.
	* testsuite/20_util/remove_cvref/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/remove_cvref/value.cc: Likewise.
	* testsuite/20_util/scoped_allocator/construct_pair_c++2a.cc:
	Likewise.
	* testsuite/20_util/shared_ptr/atomic/atomic_shared_ptr.cc:
	Likewise.
	* testsuite/20_util/shared_ptr/casts/rval.cc: Likewise.
	* testsuite/20_util/shared_ptr/comparison/cmp_c++20.cc:
	Likewise.
	* testsuite/20_util/shared_ptr/cons/alias-rval.cc: Likewise.
	* testsuite/20_util/shared_ptr/creation/92878_92947.cc:
	Likewise.
	* testsuite/20_util/shared_ptr/creation/array.cc: Likewise.
	* testsuite/20_util/shared_ptr/creation/overwrite.cc: Likewise.
	* testsuite/20_util/shared_ptr/creation/version.cc: Likewise.
	* testsuite/20_util/time_point/4.cc: Likewise.
	* testsuite/20_util/time_point/comparison_operators/three_way.cc:
	Likewise.
	* testsuite/20_util/to_address/1.cc: Likewise.
	* testsuite/20_util/to_address/1_neg.cc: Likewise.
	* testsuite/20_util/to_address/debug.cc: Likewise.
	* testsuite/20_util/to_address/lwg3545.cc: Likewise.
	* testsuite/20_util/to_chars/compare.cc: Likewise.
	* testsuite/20_util/tuple/comparison_operators/three_way.cc:
	Likewise.
	* testsuite/20_util/tuple/cons/102270.cc: Likewise.
	* testsuite/20_util/tuple/cons/constexpr_allocator_arg_t.cc:
	Likewise.
	* testsuite/20_util/tuple/constexpr_swap.cc: Likewise.
	* testsuite/20_util/type_identity/requirements/alias_decl.cc:
	Likewise.
	* testsuite/20_util/type_identity/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/type_identity/requirements/typedefs.cc:
	Likewise.
	* testsuite/20_util/typeindex/comparison_operators_c++20.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/comparison/compare_c++20.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/creation/92878_92947.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/creation/for_overwrite.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/creation/for_overwrite__neg.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/io/lwg2948.cc: Likewise.
	* testsuite/20_util/unwrap_reference/1.cc: Likewise.
	* testsuite/20_util/unwrap_reference/2.cc: Likewise.
	* testsuite/20_util/unwrap_reference/3.cc: Likewise.
	* testsuite/20_util/uses_allocator/92878_92947.cc: Likewise.
	* testsuite/20_util/uses_allocator/lwg3527.cc: Likewise.
	* testsuite/20_util/uses_allocator/make_obj.cc: Likewise.
	* testsuite/20_util/uses_allocator/uninitialized_construct.cc:
	Likewise.
	* testsuite/20_util/variant/92878_92947.cc: Likewise.
	* testsuite/20_util/variant/95915.cc: Likewise.
	* testsuite/20_util/variant/constexpr.cc: Likewise.
	* testsuite/20_util/variant/relops/three_way.cc: Likewise.
	* testsuite/20_util/variant/visit_neg.cc: Likewise.
	* testsuite/20_util/variant/visit_r.cc: Likewise.
	* testsuite/20_util/weak_ptr/atomic_weak_ptr.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/18_support/comparisons/algorithms/fallback.cc:
	Remove dg-options -std=gnu++2a.
	* testsuite/18_support/comparisons/algorithms/partial_order.cc:
	Likewise.
	* testsuite/18_support/comparisons/algorithms/strong_order.cc:
	Likewise.
	* testsuite/18_support/comparisons/algorithms/strong_order_floats.cc:
	Likewise.
	* testsuite/18_support/comparisons/algorithms/weak_order.cc:
	Likewise.
	* testsuite/18_support/comparisons/categories/94565.cc:
	Likewise.
	* testsuite/18_support/comparisons/categories/partialord.cc:
	Likewise.
	* testsuite/18_support/comparisons/categories/strongord.cc:
	Likewise.
	* testsuite/18_support/comparisons/categories/weakord.cc:
	Likewise.
	* testsuite/18_support/comparisons/categories/zero_neg.cc:
	Likewise.
	* testsuite/18_support/comparisons/common/1.cc: Likewise.
	* testsuite/18_support/comparisons/object/93479.cc: Likewise.
	* testsuite/18_support/comparisons/object/lwg3530.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/29_atomics/atomic/compare_exchange_padding.cc:
	Remove dg-options -std=gnu++2a.
	* testsuite/29_atomics/atomic/cons/value_init.cc: Likewise.
	* testsuite/29_atomics/atomic/lock_free_aliases.cc: Likewise.
	* testsuite/29_atomics/atomic/requirements/types_neg.cc:
	Likewise.
	* testsuite/29_atomics/atomic/wait_notify/1.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/100334.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/102994.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/2.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/bool.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/generic.cc: Likewise.
	* testsuite/29_atomics/atomic/wait_notify/pointers.cc: Likewise.
	* testsuite/29_atomics/atomic_flag/cons/value_init.cc: Likewise.
	* testsuite/29_atomics/atomic_flag/test/explicit.cc: Likewise.
	* testsuite/29_atomics/atomic_flag/test/implicit.cc: Likewise.
	* testsuite/29_atomics/atomic_flag/wait_notify/1.cc: Likewise.
	* testsuite/29_atomics/atomic_float/1.cc: Likewise.
	* testsuite/29_atomics/atomic_float/95282.cc: Likewise.
	* testsuite/29_atomics/atomic_float/requirements.cc: Likewise.
	* testsuite/29_atomics/atomic_float/value_init.cc: Likewise.
	* testsuite/29_atomics/atomic_float/wait_notify.cc: Likewise.
	* testsuite/29_atomics/atomic_integral/cons/value_init.cc:
	Likewise.
	* testsuite/29_atomics/atomic_integral/wait_notify.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/compare_exchange_padding.cc:
	Likewise.
	* testsuite/29_atomics/atomic_ref/deduction.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/float.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/generic.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/integral.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/pointer.cc: Likewise.
	* testsuite/29_atomics/atomic_ref/requirements.cc: Likewise.
	* testsuite/29_atomics/headers/atomic/types_std_c++20.cc:
	Likewise.
	* testsuite/29_atomics/headers/atomic/types_std_c++20_neg.cc:
	Likewise.
	* testsuite/29_atomics/headers/atomic/types_std_c++2a.cc:
	Likewise.
	* testsuite/29_atomics/headers/atomic/types_std_c++2a_neg.cc:
	Likewise.

I forgot to 'git add' these files in the commit that added the new
member function to basic_filebuf.

libstdc++-v3/ChangeLog:

	* testsuite/27_io/basic_filebuf/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_filebuf/native_handle/wchar_t/1.cc: New test.

The new __basic_file::native_handle() function can be added for C++11
and above, because the names "native_handle" and "native_handle_type"
are already reserved since C++11. Exporting those symbols from the
shared library does no harm, even if the feature gets dropped before the
C++23 standard is final.

The new member functions of std::fstream etc. are only declared for
C++26 and so are not instantiated in src/c++11/fstream-inst.cc. Declare
them with the always_inline attribute so that no symbol definitions are
needed in the library (we can change this later when C++26 support is
less experimental).

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_CHECK_FILEBUF_NATIVE_HANDLES): New
	macro.
	* config.h.in: Regenerate.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.32): Export new
	basic_filebuf members.
	* config/io/basic_file_stdio.cc (__basic_file::native_handle):
	Define new function.
	* config/io/basic_file_stdio.h (__basic_file::native_handle):
	Declare new function.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_CHECK_FILEBUF_NATIVE_HANDLES.
	* include/bits/version.def (fstream_native_handles): New macro.
	* include/bits/version.h: Regenerate.
	* include/std/fstream (basic_filebuf::native_handle)
	(basic_fstream::native_handle, basic_ifstream::native_handle)
	(basic_ofstream::native_handle): New functions.
	* src/c++11/Makefile.am: Move compilation of basic_file.cc,
	locale_init.cc and localename.cc to here.
	* src/c++11/Makefile.in: Regenerate.
	* src/c++98/locale_init.cc: Moved to...
	* src/c++11/locale_init.cc: ...here.
	* src/c++98/localename.cc: Moved to...
	* src/c++11/localename.cc: ...here.
	* src/c++98/Makefile.am: Remove basic_file.cc, locale_init.cc
	and localename.cc from here.
	* src/c++98/Makefile.in: Regenerate.
	* testsuite/27_io/basic_filebuf/native_handle/version.cc: New test.
	* testsuite/27_io/basic_fstream/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_fstream/native_handle/wchar_t/1.cc: New test.
	* testsuite/27_io/basic_ifstream/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_ifstream/native_handle/wchar_t/1.cc: New test.
	* testsuite/27_io/basic_ofstream/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_ofstream/native_handle/wchar_t/1.cc: New test.

Write a line to the log when using a testsuite_files file.

libstdc++-v3/ChangeLog:

	* testsuite/libstdc++-dg/conformance.exp: Add log line when
	using testsuite_files.

Replace dg-require-effective-target directives with a target selector on
the dg-do directive.

We can also remove { dg-require-effective-target pthread } and the
associated { dg-options "-pthread" } by allowing it to run on
non-pthread targets and conditionally adding -pthread only for pthread
targets.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/shared_ptr/atomic/3.cc: Simplify dg
	directives.
	* testsuite/20_util/shared_ptr/thread/default_weaktoshared.cc:
	Likewise.
	* testsuite/20_util/shared_ptr/thread/mutex_weaktoshared.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/allocate.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/allocate_single.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/cons.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/cons_single.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/is_equal.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/multithreaded.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/options.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/release.cc:
	Likewise.
	* testsuite/20_util/synchronized_pool_resource/release_single.cc:
	Likewise.
	* testsuite/30_threads/condition_variable_any/stop_token/wait_on.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_callback/deadlock-mt.cc:
	Likewise.
	* testsuite/30_threads/stop_token/stop_callback/destroy.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

We can also combine the { dg-require-effective-target c++2a } directive
with the dg-do selector.

We need to add the no_pch options for tests that define
_GLIBCXX_ASSERTIONS in the test, otherwise the PCH is included without
that defined.

libstdc++-v3/ChangeLog:

	* testsuite/23_containers/span/back_assert_neg.cc: Remove
	dg-options and add effective target selector to dg-do. Add
	no_pch.
	* testsuite/23_containers/span/back_neg.cc: Likewise.
	* testsuite/23_containers/span/cons_1_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/cons_2_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/first_2_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/first_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/first_neg.cc: Likewise.
	* testsuite/23_containers/span/front_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/front_neg.cc: Likewise.
	* testsuite/23_containers/span/index_op_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/index_op_neg.cc: Likewise.
	* testsuite/23_containers/span/last_2_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/last_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/last_neg.cc: Likewise.
	* testsuite/23_containers/span/subspan_2_assert_neg.cc:
	Likewise.
	* testsuite/23_containers/span/subspan_3_assert_neg.cc:
	Likewise.
	* testsuite/23_containers/span/subspan_4_assert_neg.cc:
	Likewise.
	* testsuite/23_containers/span/subspan_5_assert_neg.cc:
	Likewise.
	* testsuite/23_containers/span/subspan_6_assert_neg.cc:
	Likewise.
	* testsuite/23_containers/span/subspan_assert_neg.cc: Likewise.
	* testsuite/23_containers/span/subspan_neg.cc: Likewise.
	* testsuite/24_iterators/range_operations/advance_debug_neg.cc:
	Likewise.

The testsuite will automatically select C++23 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++26
as well.

libstdc++-v3/ChangeLog:

	* testsuite/18_support/headers/limits/synopsis_cxx23.cc: Remove
	dg-options.
	* testsuite/18_support/headers/stdfloat/types_std.cc: Likewise.
	* testsuite/18_support/type_info/constexpr.cc: Likewise.
	* testsuite/19_diagnostics/stacktrace/current.cc: Likewise.
	* testsuite/19_diagnostics/stacktrace/entry.cc: Likewise.
	* testsuite/19_diagnostics/stacktrace/stacktrace.cc: Likewise.
	* testsuite/19_diagnostics/stacktrace/synopsis.cc: Likewise.
	* testsuite/19_diagnostics/stacktrace/version.cc: Likewise.
	* testsuite/20_util/aligned_storage/deprecated-2b.cc: Likewise.
	* testsuite/20_util/aligned_union/deprecated-2b.cc: Likewise.
	* testsuite/20_util/bitset/access/constexpr.cc: Likewise.
	* testsuite/20_util/bitset/cons/constexpr_c++23.cc: Likewise.
	* testsuite/20_util/bitset/count/constexpr.cc: Likewise.
	* testsuite/20_util/bitset/ext/constexpr.cc: Likewise.
	* testsuite/20_util/bitset/operations/constexpr_c++23.cc:
	Likewise.
	* testsuite/20_util/bitset/version.cc: Likewise.
	* testsuite/20_util/from_chars/8.cc: Likewise.
	* testsuite/20_util/from_chars/constexpr.cc: Likewise.
	* testsuite/20_util/function/cons/deduction_c++23.cc: Likewise.
	* testsuite/20_util/function_objects/invoke/4.cc: Likewise.
	* testsuite/20_util/function_objects/invoke/dangling_ref.cc:
	Likewise.
	* testsuite/20_util/is_scoped_enum/value.cc: Likewise.
	* testsuite/20_util/is_scoped_enum/version.cc: Likewise.
	* testsuite/20_util/move_only_function/call.cc: Likewise.
	* testsuite/20_util/move_only_function/cons.cc: Likewise.
	* testsuite/20_util/move_only_function/move.cc: Likewise.
	* testsuite/20_util/move_only_function/version.cc: Likewise.
	* testsuite/20_util/optional/monadic/and_then.cc: Likewise.
	* testsuite/20_util/optional/monadic/or_else.cc: Likewise.
	* testsuite/20_util/optional/monadic/or_else_neg.cc: Likewise.
	* testsuite/20_util/optional/monadic/pr109242.cc: Likewise.
	* testsuite/20_util/optional/monadic/transform.cc: Likewise.
	* testsuite/20_util/pair/p2321r2.cc: Likewise.
	* testsuite/20_util/reference_from_temporary/value.cc: Likewise.
	* testsuite/20_util/reference_from_temporary/value2.cc:
	Likewise.
	* testsuite/20_util/reference_from_temporary/version.cc:
	Likewise.
	* testsuite/20_util/to_chars/constexpr.cc: Likewise.
	* testsuite/20_util/to_chars/float128_c++23.cc: Likewise.
	* testsuite/20_util/to_chars/float16_c++23.cc: Likewise.
	* testsuite/20_util/to_chars/version.cc: Likewise.
	* testsuite/20_util/to_underlying/1.cc: Likewise.
	* testsuite/20_util/to_underlying/version.cc: Likewise.
	* testsuite/20_util/tuple/p2321r2.cc: Likewise.
	* testsuite/20_util/unique_ptr/assign/constexpr.cc: Likewise.
	* testsuite/20_util/unique_ptr/comparison/constexpr.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/cons/constexpr_c++20.cc:
	Likewise.
	* testsuite/20_util/unique_ptr/creation/constexpr.cc: Likewise.
	* testsuite/20_util/unique_ptr/modifiers/constexpr.cc: Likewise.
	* testsuite/20_util/unique_ptr/specialized_algorithms/constexpr.cc: Likewise.
	* testsuite/20_util/unreachable/1.cc: Likewise.
	* testsuite/20_util/unreachable/version.cc: Likewise.
	* testsuite/20_util/uses_allocator/lwg3677.cc: Likewise.
	* testsuite/21_strings/basic_string/capacity/char/resize_and_overwrite.cc: Likewise.
	* testsuite/21_strings/basic_string/operations/contains/char.cc:
	Likewise.
	* testsuite/21_strings/basic_string/operations/contains/nonnull.cc: Likewise.
	* testsuite/21_strings/basic_string/operations/contains/wchar_t.cc: Likewise.
	* testsuite/21_strings/basic_string_view/cons/char/range_c++20.cc: Likewise.
	* testsuite/21_strings/basic_string_view/cons/wchar_t/range_c++20.cc: Likewise.
	* testsuite/21_strings/basic_string_view/operations/contains/char.cc: Likewise.
	* testsuite/21_strings/basic_string_view/operations/contains/char/2.cc: Likewise.
	* testsuite/21_strings/basic_string_view/operations/contains/nonnull.cc: Likewise.
	* testsuite/21_strings/basic_string_view/operations/contains/wchar_t.cc: Likewise.
	* testsuite/23_containers/queue/cons_from_iters.cc: Likewise.
	* testsuite/23_containers/stack/cons_from_iters.cc: Likewise.
	* testsuite/23_containers/vector/bool/element_access/1.cc:
	Likewise.
	* testsuite/24_iterators/const_iterator/1.cc: Likewise.
	* testsuite/25_algorithms/contains/1.cc: Likewise.
	* testsuite/25_algorithms/contains_subrange/1.cc: Likewise.
	* testsuite/25_algorithms/find_last/1.cc: Likewise.
	* testsuite/25_algorithms/find_last_if/1.cc: Likewise.
	* testsuite/25_algorithms/find_last_if_not/1.cc: Likewise.
	* testsuite/25_algorithms/fold_left/1.cc: Likewise.
	* testsuite/25_algorithms/fold_right/1.cc: Likewise.
	* testsuite/25_algorithms/iota/1.cc: Likewise.
	* testsuite/26_numerics/bit/bit.byteswap/byteswap.cc: Likewise.
	* testsuite/26_numerics/bit/bit.byteswap/version.cc: Likewise.
	* testsuite/26_numerics/complex/ext_c++23.cc: Likewise.
	* testsuite/26_numerics/headers/cmath/c99_classification_macros_c++23.cc: Likewise.
	* testsuite/26_numerics/headers/cmath/constexpr_std_c++23.cc:
	Likewise.
	* testsuite/26_numerics/headers/cmath/functions_std_c++23.cc:
	Likewise.
	* testsuite/26_numerics/headers/cmath/nextafter_c++23.cc:
	Likewise.
	* testsuite/26_numerics/numbers/4.cc: Likewise.
	* testsuite/27_io/basic_ostream/inserters_other/char/volatile_ptr.cc: Likewise.
	* testsuite/27_io/filesystem/path/native/conv_c++23.cc:
	Likewise.
	* testsuite/27_io/spanstream/1.cc: Likewise.
	* testsuite/27_io/spanstream/2.cc: Likewise.
	* testsuite/27_io/spanstream/version.cc: Likewise.
	* testsuite/29_atomics/atomic_float/requirements_cxx23.cc:
	Likewise.
	* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc:
	Likewise.
	* testsuite/29_atomics/headers/stdatomic.h/version.cc: Likewise.
	* testsuite/30_threads/packaged_task/cons/deduction_c++23.cc:
	Likewise.
	* testsuite/experimental/filesystem/path/native/conv_c++23.cc:
	Likewise.
	* testsuite/std/ranges/adaptors/adjacent/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/adjacent_transform/1.cc:
	Likewise.
	* testsuite/std/ranges/adaptors/as_const/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/as_rvalue/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/chunk/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/chunk_by/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/enumerate/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/join_with/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/lwg3715.cc: Likewise.
	* testsuite/std/ranges/adaptors/slide/1.cc: Likewise.
	* testsuite/std/ranges/adaptors/stride/1.cc: Likewise.
	* testsuite/std/ranges/cartesian_product/1.cc: Likewise.
	* testsuite/std/ranges/range_adaptor_closure.cc: Likewise.
	* testsuite/std/ranges/repeat/1.cc: Likewise.
	* testsuite/std/ranges/version_c++23.cc: Likewise.
	* testsuite/std/ranges/zip/1.cc: Likewise.
	* testsuite/std/ranges/zip_transform/1.cc: Likewise.

The testsuite will automatically select C++23 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++26
as well.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/expected/assign.cc: Remove dg-options.
	* testsuite/20_util/expected/bad.cc: Likewise.
	* testsuite/20_util/expected/cons.cc: Likewise.
	* testsuite/20_util/expected/equality.cc: Likewise.
	* testsuite/20_util/expected/illformed_neg.cc: Likewise.
	* testsuite/20_util/expected/lwg3877.cc: Likewise.
	* testsuite/20_util/expected/lwg3938.cc: Likewise.
	* testsuite/20_util/expected/monadic.cc: Likewise.
	* testsuite/20_util/expected/observers.cc: Likewise.
	* testsuite/20_util/expected/requirements.cc: Likewise.
	* testsuite/20_util/expected/swap.cc: Likewise.
	* testsuite/20_util/expected/synopsis.cc: Likewise.
	* testsuite/20_util/expected/unexpected.cc: Likewise.
	* testsuite/20_util/expected/version.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/duration/arithmetic/overflow_c++20.cc:
	Remove dg-options.
	* testsuite/20_util/duration/io.cc: Likewise.
	* testsuite/std/time/clock/file/io.cc: Likewise.
	* testsuite/std/time/clock/file/members.cc: Likewise.
	* testsuite/std/time/clock/file/overview.cc: Likewise.
	* testsuite/std/time/clock/gps/1.cc: Likewise.
	* testsuite/std/time/clock/gps/io.cc: Likewise.
	* testsuite/std/time/clock/local/io.cc: Likewise.
	* testsuite/std/time/clock/system/io.cc: Likewise.
	* testsuite/std/time/clock/tai/1.cc: Likewise.
	* testsuite/std/time/clock/tai/io.cc: Likewise.
	* testsuite/std/time/clock/utc/1.cc: Likewise.
	* testsuite/std/time/clock/utc/io.cc: Likewise.
	* testsuite/std/time/clock/utc/leap_second_info.cc: Likewise.
	* testsuite/std/time/day/1.cc: Likewise.
	* testsuite/std/time/day/io.cc: Likewise.
	* testsuite/std/time/exceptions.cc: Likewise.
	* testsuite/std/time/format.cc: Likewise.
	* testsuite/std/time/hh_mm_ss/1.cc: Likewise.
	* testsuite/std/time/hh_mm_ss/109772.cc: Likewise.
	* testsuite/std/time/hh_mm_ss/io.cc: Likewise.
	* testsuite/std/time/is_am/1.cc: Likewise.
	* testsuite/std/time/is_pm/1.cc: Likewise.
	* testsuite/std/time/make12/1.cc: Likewise.
	* testsuite/std/time/make24/1.cc: Likewise.
	* testsuite/std/time/month/1.cc: Likewise.
	* testsuite/std/time/month/io.cc: Likewise.
	* testsuite/std/time/month_day/1.cc: Likewise.
	* testsuite/std/time/month_day/io.cc: Likewise.
	* testsuite/std/time/month_day_last/1.cc: Likewise.
	* testsuite/std/time/month_day_last/io.cc: Likewise.
	* testsuite/std/time/month_weekday/1.cc: Likewise.
	* testsuite/std/time/month_weekday/io.cc: Likewise.
	* testsuite/std/time/month_weekday_last/1.cc: Likewise.
	* testsuite/std/time/month_weekday_last/io.cc: Likewise.
	* testsuite/std/time/parse.cc: Likewise.
	* testsuite/std/time/syn_c++20.cc: Likewise.
	* testsuite/std/time/time_zone/get_info_local.cc: Likewise.
	* testsuite/std/time/time_zone/get_info_sys.cc: Likewise.
	* testsuite/std/time/time_zone/requirements.cc: Likewise.
	* testsuite/std/time/traits/is_clock.cc: Likewise.
	* testsuite/std/time/tzdb/1.cc: Likewise.
	* testsuite/std/time/tzdb/leap_seconds.cc: Likewise.
	* testsuite/std/time/tzdb_list/1.cc: Likewise.
	* testsuite/std/time/tzdb_list/requirements.cc: Likewise.
	* testsuite/std/time/weekday/1.cc: Likewise.
	* testsuite/std/time/weekday/io.cc: Likewise.
	* testsuite/std/time/weekday_indexed/io.cc: Likewise.
	* testsuite/std/time/weekday_last/1.cc: Likewise.
	* testsuite/std/time/weekday_last/io.cc: Likewise.
	* testsuite/std/time/year/1.cc: Likewise.
	* testsuite/std/time/year/2.cc: Likewise.
	* testsuite/std/time/year/io.cc: Likewise.
	* testsuite/std/time/weekday_indexed/1.cc: Likewise.
	* testsuite/std/time/year_month/1.cc: Likewise.
	* testsuite/std/time/year_month/2.cc: Likewise.
	* testsuite/std/time/year_month/io.cc: Likewise.
	* testsuite/std/time/year_month_day/1.cc: Likewise.
	* testsuite/std/time/year_month_day/2.cc: Likewise.
	* testsuite/std/time/year_month_day/3.cc: Likewise.
	* testsuite/std/time/year_month_day/4.cc: Likewise.
	* testsuite/std/time/year_month_day/io.cc: Likewise.
	* testsuite/std/time/year_month_day_last/1.cc: Likewise.
	* testsuite/std/time/year_month_day_last/2.cc: Likewise.
	* testsuite/std/time/year_month_day_last/io.cc: Likewise.
	* testsuite/std/time/year_month_weekday/1.cc: Likewise.
	* testsuite/std/time/year_month_weekday/2.cc: Likewise.
	* testsuite/std/time/year_month_weekday/3.cc: Likewise.
	* testsuite/std/time/year_month_weekday/io.cc: Likewise.
	* testsuite/std/time/year_month_weekday_last/1.cc: Likewise.
	* testsuite/std/time/year_month_weekday_last/2.cc: Likewise.
	* testsuite/std/time/year_month_weekday_last/io.cc: Likewise.
	* testsuite/std/time/zoned_time/1.cc: Likewise.
	* testsuite/std/time/zoned_time/custom.cc: Likewise.
	* testsuite/std/time/zoned_time/deduction.cc: Likewise.
	* testsuite/std/time/zoned_time/io.cc: Likewise.
	* testsuite/std/time/zoned_time/req_neg.cc: Likewise.
	* testsuite/std/time/zoned_time/requirements.cc: Likewise.
	* testsuite/std/time/zoned_traits.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/std/format/arguments/args.cc: Remove dg-options.
	* testsuite/std/format/arguments/lwg3810.cc: Likewise.
	* testsuite/std/format/error.cc: Likewise.
	* testsuite/std/format/format_string.cc: Likewise.
	* testsuite/std/format/formatter/concept.cc: Likewise.
	* testsuite/std/format/formatter/ext_float.cc: Likewise.
	* testsuite/std/format/formatter/requirements.cc: Likewise.
	* testsuite/std/format/functions/107871.cc: Likewise.
	* testsuite/std/format/functions/format.cc: Likewise.
	* testsuite/std/format/functions/format_to.cc: Likewise.
	* testsuite/std/format/functions/format_to_n.cc: Likewise.
	* testsuite/std/format/functions/size.cc: Likewise.
	* testsuite/std/format/functions/vformat_to.cc: Likewise.
	* testsuite/std/format/parse_ctx.cc: Likewise.
	* testsuite/std/format/string.cc: Likewise.
	* testsuite/std/format/string_neg.cc: Likewise.
	* testsuite/std/format/functions/format_c++23.cc: Removed.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/20_util/function_objects/range.cmp/equal_to.cc:
	Remove dg-options.
	* testsuite/20_util/function_objects/range.cmp/greater.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/greater_equal.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/less.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/less_equal.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/lwg3530.cc:
	Likewise.
	* testsuite/20_util/function_objects/range.cmp/not_equal_to.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/construct_at/1.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/construct_at/92878_92947.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/construct_at/95788.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/destroy/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_default_construct/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/94017.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/94017.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_move/constrained.cc:
	Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/adjacent_find/constexpr.cc: Likewise.
	* testsuite/25_algorithms/adjacent_find/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/all_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/all_of/constrained.cc: Likewise.
	* testsuite/25_algorithms/any_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/any_of/constrained.cc: Likewise.
	* testsuite/25_algorithms/binary_search/constexpr.cc: Likewise.
	* testsuite/25_algorithms/binary_search/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/clamp/constrained.cc: Likewise.
	* testsuite/25_algorithms/constexpr_macro.cc: Likewise.
	* testsuite/25_algorithms/copy/95578.cc: Likewise.
	* testsuite/25_algorithms/copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/copy/debug/constexpr_neg.cc: Likewise.
	* testsuite/25_algorithms/copy_backward/95578.cc: Likewise.
	* testsuite/25_algorithms/copy_backward/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy_backward/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/copy_backward/debug/constexpr_neg.cc:
	Likewise.
	* testsuite/25_algorithms/copy_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/copy_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/copy_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/count/constexpr.cc: Likewise.
	* testsuite/25_algorithms/count/constrained.cc: Likewise.
	* testsuite/25_algorithms/count_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/count_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/cpp_lib_constexpr.cc: Likewise.
	* testsuite/25_algorithms/equal/95578.cc: Likewise.
	* testsuite/25_algorithms/equal/constexpr.cc: Likewise.
	* testsuite/25_algorithms/equal/constexpr_neg.cc: Likewise.
	* testsuite/25_algorithms/equal/constrained.cc: Likewise.
	* testsuite/25_algorithms/equal/debug/constexpr_neg.cc:
	Likewise.
	* testsuite/25_algorithms/equal_range/constexpr.cc: Likewise.
	* testsuite/25_algorithms/equal_range/constrained.cc: Likewise.
	* testsuite/25_algorithms/fill/94017.cc: Likewise.
	* testsuite/25_algorithms/fill/constexpr.cc: Likewise.
	* testsuite/25_algorithms/fill/constrained.cc: Likewise.
	* testsuite/25_algorithms/fill_n/94017.cc: Likewise.
	* testsuite/25_algorithms/fill_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/fill_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/find/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find/constrained.cc: Likewise.
	* testsuite/25_algorithms/find_end/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_end/constrained.cc: Likewise.
	* testsuite/25_algorithms/find_first_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_first_of/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/find_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/find_if_not/constexpr.cc: Likewise.
	* testsuite/25_algorithms/find_if_not/constrained.cc: Likewise.
	* testsuite/25_algorithms/for_each/constexpr.cc: Likewise.
	* testsuite/25_algorithms/for_each/constrained.cc: Likewise.
	* testsuite/25_algorithms/generate/constexpr.cc: Likewise.
	* testsuite/25_algorithms/generate/constrained.cc: Likewise.
	* testsuite/25_algorithms/generate_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/generate_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/heap/constrained.cc: Likewise.
	* testsuite/25_algorithms/includes/constrained.cc: Likewise.
	* testsuite/25_algorithms/inplace_merge/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/is_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_heap_until/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_partitioned/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_partitioned/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/is_permutation/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_permutation/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/is_sorted/constexpr.cc: Likewise.
	* testsuite/25_algorithms/is_sorted/constrained.cc: Likewise.
	* testsuite/25_algorithms/is_sorted_until/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/is_sorted_until/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/iter_swap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/lexicographical_compare/93972.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare/95578.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare_three_way/1.cc:
	Likewise.
	* testsuite/25_algorithms/lexicographical_compare_three_way/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/constexpr.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/constrained.cc: Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_pred_neg.cc:
	Likewise.
	* testsuite/25_algorithms/lower_bound/debug/constexpr_valid_range_neg.cc:
	Likewise.
	* testsuite/25_algorithms/make_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/max/constrained.cc: Likewise.
	* testsuite/25_algorithms/max_element/constrained.cc: Likewise.
	* testsuite/25_algorithms/merge/constexpr.cc: Likewise.
	* testsuite/25_algorithms/merge/constrained.cc: Likewise.
	* testsuite/25_algorithms/min/constrained.cc: Likewise.
	* testsuite/25_algorithms/min_element/constrained.cc: Likewise.
	* testsuite/25_algorithms/minmax/constrained.cc: Likewise.
	* testsuite/25_algorithms/minmax_element/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/mismatch/constexpr.cc: Likewise.
	* testsuite/25_algorithms/mismatch/constrained.cc: Likewise.
	* testsuite/25_algorithms/move/93872.cc: Likewise.
	* testsuite/25_algorithms/move/95578.cc: Likewise.
	* testsuite/25_algorithms/move/constexpr.cc: Likewise.
	* testsuite/25_algorithms/move/constrained.cc: Likewise.
	* testsuite/25_algorithms/move_backward/93872.cc: Likewise.
	* testsuite/25_algorithms/move_backward/95578.cc: Likewise.
	* testsuite/25_algorithms/move_backward/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/next_permutation/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/next_permutation/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/none_of/constexpr.cc: Likewise.
	* testsuite/25_algorithms/none_of/constrained.cc: Likewise.
	* testsuite/25_algorithms/nth_element/constexpr.cc: Likewise.
	* testsuite/25_algorithms/nth_element/constrained.cc: Likewise.
	* testsuite/25_algorithms/partial_sort/constexpr.cc: Likewise.
	* testsuite/25_algorithms/partial_sort/constrained.cc: Likewise.
	* testsuite/25_algorithms/partial_sort_copy/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/partial_sort_copy/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/partition/constexpr.cc: Likewise.
	* testsuite/25_algorithms/partition/constrained.cc: Likewise.
	* testsuite/25_algorithms/partition_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/partition_copy/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/partition_point/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/partition_point/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/pop_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/prev_permutation/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/prev_permutation/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/push_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove/constrained.cc: Likewise.
	* testsuite/25_algorithms/remove_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/remove_copy_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove_copy_if/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/remove_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/remove_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/replace/constrained.cc: Likewise.
	* testsuite/25_algorithms/replace_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/replace_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/replace_copy_if/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/replace_copy_if/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/replace_if/constexpr.cc: Likewise.
	* testsuite/25_algorithms/replace_if/constrained.cc: Likewise.
	* testsuite/25_algorithms/reverse/constexpr.cc: Likewise.
	* testsuite/25_algorithms/reverse/constrained.cc: Likewise.
	* testsuite/25_algorithms/reverse_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/reverse_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/rotate/constexpr.cc: Likewise.
	* testsuite/25_algorithms/rotate/constrained.cc: Likewise.
	* testsuite/25_algorithms/rotate_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/rotate_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/sample/constrained.cc: Likewise.
	* testsuite/25_algorithms/search/constexpr.cc: Likewise.
	* testsuite/25_algorithms/search/constrained.cc: Likewise.
	* testsuite/25_algorithms/search_n/97828.cc: Likewise.
	* testsuite/25_algorithms/search_n/constexpr.cc: Likewise.
	* testsuite/25_algorithms/search_n/constrained.cc: Likewise.
	* testsuite/25_algorithms/set_difference/constexpr.cc: Likewise.
	* testsuite/25_algorithms/set_difference/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/set_intersection/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/set_intersection/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/set_symmetric_difference/constexpr.cc:
	Likewise.
	* testsuite/25_algorithms/set_symmetric_difference/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/set_union/constexpr.cc: Likewise.
	* testsuite/25_algorithms/set_union/constrained.cc: Likewise.
	* testsuite/25_algorithms/shift_left/1.cc: Likewise.
	* testsuite/25_algorithms/shift_right/1.cc: Likewise.
	* testsuite/25_algorithms/shuffle/constrained.cc: Likewise.
	* testsuite/25_algorithms/sort/constexpr.cc: Likewise.
	* testsuite/25_algorithms/sort/constrained.cc: Likewise.
	* testsuite/25_algorithms/sort_heap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/stable_partition/constrained.cc:
	Likewise.
	* testsuite/25_algorithms/stable_sort/constrained.cc: Likewise.
	* testsuite/25_algorithms/swap/constexpr.cc: Likewise.
	* testsuite/25_algorithms/swap_ranges/constexpr.cc: Likewise.
	* testsuite/25_algorithms/swap_ranges/constrained.cc: Likewise.
	* testsuite/25_algorithms/transform/constexpr.cc: Likewise.
	* testsuite/25_algorithms/transform/constrained.cc: Likewise.
	* testsuite/25_algorithms/unique/constexpr.cc: Likewise.
	* testsuite/25_algorithms/unique/constrained.cc: Likewise.
	* testsuite/25_algorithms/unique_copy/constexpr.cc: Likewise.
	* testsuite/25_algorithms/unique_copy/constrained.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/constexpr.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/constrained.cc: Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_neg.cc:
	Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_pred_neg.cc:
	Likewise.
	* testsuite/25_algorithms/upper_bound/debug/constexpr_valid_range_neg.cc:
	Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

libstdc++-v3/ChangeLog:

	* testsuite/std/concepts/1.cc: Remove dg-options.
	* testsuite/std/concepts/2.cc: Likewise.
	* testsuite/std/concepts/concepts.callable/invocable.cc:
	Likewise.
	* testsuite/std/concepts/concepts.callable/regular_invocable.cc:
	Likewise.
	* testsuite/std/concepts/concepts.callable/relation.cc:
	Likewise.
	* testsuite/std/concepts/concepts.callable/strictweakorder.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/floating_point.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/integral.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/signed_integral.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.arithmetic/unsigned_integral.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.assignable/1.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.common/1.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.commonref/1.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.constructible/1.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.convertible/1.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.copyconstructible/1.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.defaultinitializable/1.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.defaultinitializable/lwg3149.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.derived/1.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.destructible/1.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.moveconstructible/1.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.same/1.cc:
	Likewise.
	* testsuite/std/concepts/concepts.lang/concept.swappable/swap.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.swappable/swappable.cc: Likewise.
	* testsuite/std/concepts/concepts.lang/concept.swappable/swappable_with.cc: Likewise.
	* testsuite/std/concepts/concepts.object/copyable.cc: Likewise.
	* testsuite/std/concepts/concepts.object/movable.cc: Likewise.
	* testsuite/std/concepts/concepts.object/regular.cc: Likewise.
	* testsuite/std/concepts/concepts.object/semiregular.cc:
	Likewise.
	* testsuite/std/ranges/97600.cc: Likewise.
	* testsuite/std/ranges/access/101782.cc: Likewise.
	* testsuite/std/ranges/access/begin.cc: Likewise.
	* testsuite/std/ranges/access/begin_neg.cc: Likewise.
	* testsuite/std/ranges/access/cbegin.cc: Likewise.
	* testsuite/std/ranges/access/cdata.cc: Likewise.
	* testsuite/std/ranges/access/cend.cc: Likewise.
	* testsuite/std/ranges/access/crbegin.cc: Likewise.
	* testsuite/std/ranges/access/crend.cc: Likewise.
	* testsuite/std/ranges/access/data.cc: Likewise.
	* testsuite/std/ranges/access/empty.cc: Likewise.
	* testsuite/std/ranges/access/end.cc: Likewise.
	* testsuite/std/ranges/access/end_neg.cc: Likewise.
	* testsuite/std/ranges/access/lwg3467.cc: Likewise.
	* testsuite/std/ranges/access/p2602.cc: Likewise.
	* testsuite/std/ranges/access/rbegin.cc: Likewise.
	* testsuite/std/ranges/access/rend.cc: Likewise.
	* testsuite/std/ranges/access/size.cc: Likewise.
	* testsuite/std/ranges/access/size_neg.cc: Likewise.
	* testsuite/std/ranges/access/ssize.cc: Likewise.
	* testsuite/std/ranges/adaptors/100479.cc: Likewise.
	* testsuite/std/ranges/adaptors/100577.cc: Likewise.
	* testsuite/std/ranges/adaptors/93978.cc: Likewise.
	* testsuite/std/ranges/adaptors/95322.cc: Likewise.
	* testsuite/std/ranges/adaptors/99433.cc: Likewise.
	* testsuite/std/ranges/adaptors/all.cc: Likewise.
	* testsuite/std/ranges/adaptors/common.cc: Likewise.
	* testsuite/std/ranges/adaptors/conditionally_borrowed.cc:
	Likewise.
	* testsuite/std/ranges/adaptors/counted.cc: Likewise.
	* testsuite/std/ranges/adaptors/detail/copyable_box.cc:
	Likewise.
	* testsuite/std/ranges/adaptors/drop.cc: Likewise.
	* testsuite/std/ranges/adaptors/drop_while.cc: Likewise.
	* testsuite/std/ranges/adaptors/elements.cc: Likewise.
	* testsuite/std/ranges/adaptors/filter.cc: Likewise.
	* testsuite/std/ranges/adaptors/join.cc: Likewise.
	* testsuite/std/ranges/adaptors/lazy_split.cc: Likewise.
	* testsuite/std/ranges/adaptors/lazy_split_neg.cc: Likewise.
	* testsuite/std/ranges/adaptors/lwg3286.cc: Likewise.
	* testsuite/std/ranges/adaptors/lwg3313_neg.cc: Likewise.
	* testsuite/std/ranges/adaptors/lwg3325_neg.cc: Likewise.
	* testsuite/std/ranges/adaptors/lwg3406.cc: Likewise.
	* testsuite/std/ranges/adaptors/p1739.cc: Likewise.
	* testsuite/std/ranges/adaptors/p2281.cc: Likewise.
	* testsuite/std/ranges/adaptors/p2770r0.cc: Likewise.
	* testsuite/std/ranges/adaptors/reverse.cc: Likewise.
	* testsuite/std/ranges/adaptors/sizeof.cc: Likewise.
	* testsuite/std/ranges/adaptors/split.cc: Likewise.
	* testsuite/std/ranges/adaptors/take.cc: Likewise.
	* testsuite/std/ranges/adaptors/take_while.cc: Likewise.
	* testsuite/std/ranges/adaptors/transform.cc: Likewise.
	* testsuite/std/ranges/empty_view.cc: Likewise.
	* testsuite/std/ranges/headers/ranges/synopsis.cc: Likewise.
	* testsuite/std/ranges/iota/difference_type.cc: Likewise.
	* testsuite/std/ranges/iota/iota_view.cc: Likewise.
	* testsuite/std/ranges/iota/iterator.cc: Likewise.
	* testsuite/std/ranges/iota/lwg3292_neg.cc: Likewise.
	* testsuite/std/ranges/iota/max_size_type.cc: Likewise.
	* testsuite/std/ranges/istream_view.cc: Likewise.
	* testsuite/std/ranges/p2259.cc: Likewise.
	* testsuite/std/ranges/p2325.cc: Likewise.
	* testsuite/std/ranges/p2367.cc: Likewise.
	* testsuite/std/ranges/range.cc: Likewise.
	* testsuite/std/ranges/refinements.cc: Likewise.
	* testsuite/std/ranges/safe_range.cc: Likewise.
	* testsuite/std/ranges/safe_range_types.cc: Likewise.
	* testsuite/std/ranges/single_view.cc: Likewise.
	* testsuite/std/ranges/sized.cc: Likewise.
	* testsuite/std/ranges/subrange/1.cc: Likewise.
	* testsuite/std/ranges/subrange/97512.cc: Likewise.
	* testsuite/std/ranges/subrange/constexpr.cc: Likewise.
	* testsuite/std/ranges/subrange/lwg3282_neg.cc: Likewise.
	* testsuite/std/ranges/subrange/lwg3286.cc: Likewise.
	* testsuite/std/ranges/subrange/lwg3433.cc: Likewise.
	* testsuite/std/ranges/subrange/sizeof.cc: Likewise.
	* testsuite/std/ranges/subrange/tuple_like.cc: Likewise.
	* testsuite/std/ranges/view.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well.

There doesn't seem to be any reason they need to use strict -std=c++20
mode, so don't add the { dg-add-options strict_std } directive, just let
them use strict or non-strict modes.

libstdc++-v3/ChangeLog:

	* testsuite/21_strings/headers/cuchar/functions_std_cxx20.cc:
	Remove dg-options.
	* testsuite/23_containers/span/contiguous_range_neg.cc:
	Likewise.
	* testsuite/23_containers/span/everything.cc: Likewise.

The testsuite will automatically select C++20 for these tests now, and
removing the hardcoded -std option allows them to be tested for C++23
and C++26 as well. Because they test a problem seen with -std=c++20 add
the new { dg-add-options strict_std } directive so that the test runner
uses -std=c++NN not -std=gnu++NN.

libstdc++-v3/ChangeLog:

	* testsuite/24_iterators/reverse_iterator/100639.cc: Remove
	dg-options and add dg-add-options strict_std.
	* testsuite/std/ranges/iota/93267.cc: Likewise.
	* testsuite/std/ranges/iota/96042.cc: Likewise.
	* testsuite/std/ranges/iota/size.cc: Likewise.
	* testsuite/std/ranges/subrange/96042.cc: Likewise.

These tests can (and should) also be run for later standards, so replace
the { dg-options "-std=c++17" } with { dg-add-options strict_std }.

	* testsuite/tr1/5_numerical_facilities/special_functions/07_conf_hyperg/compile_cxx17.cc:
	Replace dg-options -std=c++17 with dg-add-options strict_std.
	* testsuite/tr1/5_numerical_facilities/special_functions/17_hyperg/compile_cxx17.cc:
	Likewise.

These tests can (and should) also be run for later standards, so replace
the { dg-options "-std=c++11" } with { dg-add-options strict_std } and a
target selector for c++11.

libstdc++-v3/ChangeLog:

	* testsuite/23_containers/deque/48101-2_neg.cc: Replace
	dg-options with target selector.
	* testsuite/23_containers/forward_list/48101-2_neg.cc: Likewise.
	* testsuite/23_containers/list/48101-2_neg.cc: Likewise.
	* testsuite/23_containers/map/48101-2_neg.cc: Likewise.
	* testsuite/23_containers/map/48101_neg.cc: Likewise.
	* testsuite/23_containers/multimap/48101-2_neg.cc: Likewise.
	* testsuite/23_containers/multimap/48101_neg.cc: Likewise.
	* testsuite/23_containers/multiset/48101-2_neg.cc: Likewise.
	* testsuite/23_containers/set/48101-2_neg.cc: Likewise.
	* testsuite/23_containers/unordered_map/48101-2_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_multimap/48101-2_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_multiset/48101-2_neg.cc:
	Likewise.
	* testsuite/23_containers/unordered_set/48101-2_neg.cc:
	Likewise.
	* testsuite/23_containers/vector/48101-2_neg.cc: Likewise.

This copies the code from the compiler's gcc/testsuite/lib/g++-dg.exp so
that each test can be run multiple times, with different -std options.
This means that we can remove most { dg-options "-std=gnu++20" }
directives from tests, because the testsuite will automatically select
a set of -std options that includes that version.

Tests that should only run for a specific standard (e.g. ones that use
something like { dg-do run { target c++11_only } }) should still specify
that standard with { dg-options "-std=gnu++11" }, which overrides the
automatic selection. But a dg-options that selects a newer standard than
the default can be removed, because that standard will be selected
automatically based on a selector like { target c++20 } in the dg-do
directive. This will allow those tests to be run for more than just the
one they currently hardcode, so that e.g. std::format tests can be run
for all of C++20, C++23 and C++26. Currently that has to be done by
adding a second test file that uses a different dg-options line.

By default most tests will continue to run with only the default dialect
(currently -std=gnu++17) so that the time to run the entire testsuite is
not increased. We can revisit this later if increasing the testsuite
time (and coverage) is acceptable. Libstdc++ developers can easily
override the defaults to run for multiple versions. To test all
versions, either add 'set v3_std_list { 98 11 14 17 20 23 26 }' to
~/.dejagnurc or define GLIBCXX_TESTSUITE_STDS="98,11,14,17,20,23,26" in
the environment.

This should be more efficient than the current way to test with multple
standards, i.e. --target_board=unix{-std=c++14,-std=c++17,-std=c++20},
because today all tests with an explicit -std option hardcoded in them
get run for each target board variation but using the exact same
hardcoded -std every time. With the new approach you can just use the
default --target_board=unix and set GLIBCXX_TESTSUITE_STDS="14,17,20"
and now a test that has { target c++20 } will only run once (and be
UNSUPPORTED twice), instead of running with identical options three
times.

In order to support ~/.dejagnurc and $DEJAGNU files that need to work
with versions of GCC without this change, a new variable is added to
site.tmp to detect whether v3_std_list is supported. That allows e.g.

if { [info exists v3-use-std-list] } {
  set v3_std_list { 11 17 23 }
  set target_list { "unix{,-m32}" }
} else {
  set target_list { "unix{,-std=gnu++2b,-std=gnu++11,-m32}" }
}

libstdc++-v3/ChangeLog:

	* doc/xml/manual/test.xml: Update documentation on running and
	writing tests.
	* doc/html/manual/test.html: Regenerate.
	* testsuite/Makefile.am: Add v3-use-std-list to site.tmp
	* testsuite/Makefile.in: Regenerate.
	* testsuite/lib/dg-options.exp (add_options_for_strict_std): New
	proc.
	* testsuite/lib/libstdc++.exp (search_for): New utility proc.
	(v3-dg-runtest): New proc to replace dg-runtest.
	* testsuite/libstdc++-dg/conformance.exp: Use v3-dg-runtest.

This test fails when run as C++23 because the <bits/stdc++.h> PCH
includes <stdatomic.h> which declares ::memory_order, invalidating the
test's assumptions. Disable PCH so that the test verifies that <atomic>
doesn't declare ::memory_order, as originally intended.

Also fix the using-declaration which would be invalid even if the type
was declared in the global namespace, and adjust the expected error.

libstdc++-v3/ChangeLog:

	* testsuite/29_atomics/headers/atomic/types_std_c++2a_neg.cc:
	Fix test to work for C++23 and C++26 too.