Add '-Wno-complain-wrong-lang', and use it in 'gcc/testsuite/lib/target-supports.exp:check_compile' and elsewhere

I noticed that GCC/Rust recently lost all LTO variants in torture testing:

     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O0  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O1  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O2  (test for excess errors)
    -PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (test for excess errors)
    -PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O3 -g  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -Os  (test for excess errors)

Etc.

The reason is that when probing for availability of LTO, we run into:

    spawn [...]/build-gcc/gcc/testsuite/rust/../../gccrs -B[...]/build-gcc/gcc/testsuite/rust/../../ -fdiagnostics-plain-output -frust-incomplete-and-experimental-compiler-do-not-use -flto -c -o lto8274.o lto8274.c
    cc1: warning: command-line option '-frust-incomplete-and-experimental-compiler-do-not-use' is valid for Rust but not for C

For GCC/Rust testing, this flag is (as of recently) defaulted in
'gcc/testsuite/lib/rust.exp:rust_init':

    lappend ALWAYS_RUSTFLAGS "additional_flags=-frust-incomplete-and-experimental-compiler-do-not-use"

A few more "command-line option [...] is valid for [...] but not for [...]"
instances were found in the test suite logs, when more than one language is
involved.

With '-Wno-complain-wrong-lang' used in
'gcc/testsuite/lib/target-supports.exp:check_compile', we get back:

     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O0  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O1  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O2  (test for excess errors)
    +PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O2 -flto -fno-use-linker-plugin -flto-partition=none  (test for excess errors)
    +PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -O3 -g  (test for excess errors)
     PASS: rust/compile/torture/all_doc_comment_line_blocks.rs   -Os  (test for excess errors)

Etc., and in total:

                    === rust Summary for unix ===

    # of expected passes            [-4990-]{+6718+}
    # of expected failures          [-39-]{+51+}

Anything that 'gcc/opts-global.cc:complain_wrong_lang' might do is cut
short by '-Wno-complain-wrong-lang', not just the one 'warning'
diagnostic.  This corresponds to what already exists via
'lang_hooks.complain_wrong_lang_p'.

The 'gcc/opts-common.cc:prune_options' changes follow the same rationale
as PR67640 "driver passes -fdiagnostics-color= always last": we need to
process '-Wno-complain-wrong-lang' early, so that it properly affects
other options appearing before it on the command line.

	gcc/
	* common.opt (-Wcomplain-wrong-lang): New.
	* doc/invoke.texi (-Wno-complain-wrong-lang): Document it.
	* opts-common.cc (prune_options): Handle it.
	* opts-global.cc (complain_wrong_lang): Use it.
	gcc/testsuite/
	* gcc.dg/Wcomplain-wrong-lang-1.c: New.
	* gcc.dg/Wcomplain-wrong-lang-2.c: Likewise.
	* gcc.dg/Wcomplain-wrong-lang-3.c: Likewise.
	* gcc.dg/Wcomplain-wrong-lang-4.c: Likewise.
	* gcc.dg/Wcomplain-wrong-lang-5.c: Likewise.
	* lib/target-supports.exp (check_compile): Use
	'-Wno-complain-wrong-lang'.
	* g++.dg/abi/empty12.C: Likewise.
	* g++.dg/abi/empty13.C: Likewise.
	* g++.dg/abi/empty14.C: Likewise.
	* g++.dg/abi/empty15.C: Likewise.
	* g++.dg/abi/empty16.C: Likewise.
	* g++.dg/abi/empty17.C: Likewise.
	* g++.dg/abi/empty18.C: Likewise.
	* g++.dg/abi/empty19.C: Likewise.
	* g++.dg/abi/empty22.C: Likewise.
	* g++.dg/abi/empty25.C: Likewise.
	* g++.dg/abi/empty26.C: Likewise.
	* gfortran.dg/bind-c-contiguous-1.f90: Likewise.
	* gfortran.dg/bind-c-contiguous-4.f90: Likewise.
	* gfortran.dg/bind-c-contiguous-5.f90: Likewise.
	libgomp/
	* testsuite/libgomp.fortran/alloc-10.f90: Use
	'-Wno-complain-wrong-lang'.
	* testsuite/libgomp.fortran/alloc-11.f90: Likewise.
	* testsuite/libgomp.fortran/alloc-7.f90: Likewise.
	* testsuite/libgomp.fortran/alloc-9.f90: Likewise.
	* testsuite/libgomp.fortran/allocate-1.f90: Likewise.
	* testsuite/libgomp.fortran/depend-4.f90: Likewise.
	* testsuite/libgomp.fortran/depend-5.f90: Likewise.
	* testsuite/libgomp.fortran/depend-6.f90: Likewise.
	* testsuite/libgomp.fortran/depend-7.f90: Likewise.
	* testsuite/libgomp.fortran/depend-inoutset-1.f90: Likewise.
	* testsuite/libgomp.fortran/examples-4/declare_target-1.f90:
	Likewise.
	* testsuite/libgomp.fortran/examples-4/declare_target-2.f90:
	Likewise.
	* testsuite/libgomp.fortran/order-reproducible-1.f90: Likewise.
	* testsuite/libgomp.fortran/order-reproducible-2.f90: Likewise.
	* testsuite/libgomp.oacc-fortran/parallel-dims.f90: Likewise.
	* testsuite/libgomp.fortran/task-detach-6.f90: Remove left-over
	'dg-prune-output'.

For example:

    configure: error: "libffi has not been ported to nvptx-unknown-none."

Follow-up to commit a75f038c
"gccrs: Add config-lang.in", which said:

> This was a copy/paste from gccgo front-end. We do not use any of the
> target_libs yet, [...]

	gcc/rust/
	* config-lang.in (target_libs): Remove.

Already in the first revision of 'contrib/config-list.mk', i686-symbolics-gnu
has been present, but it's not clear to me whether that was meant to be
Symbolics as in the manufacturer, <https://en.wikipedia.org/wiki/Symbolics>,
with GNU (that is, GNU/Hurd) kernel/operating system (user land), or Symbolics
kernel with GNU operating system (user land)?

I can't find any mention of "Symbolics" in the history of 'config.sub'
upstream.

Either way, GCC configures i686-symbolics-gnu exactly the same as i686-gnu:

    $ sed -n -e '/Using .* host machine hooks\.$/q' -e '/^Using the following target machine macro files:$/,$p' log/i686-gnu-make.out
    Using the following target machine macro files:
            [...]/gcc/config/vxworks-dummy.h
            [...]/gcc/config/i386/i386.h
            [...]/gcc/config/i386/unix.h
            [...]/gcc/config/i386/att.h
            [...]/gcc/config/elfos.h
            [...]/gcc/config/gnu-user.h
            [...]/gcc/config/glibc-stdint.h
            [...]/gcc/config/i386/gnu-user-common.h
            [...]/gcc/config/i386/gnu-user.h
            [...]/gcc/config/gnu.h
            [...]/gcc/config/i386/gnu.h
            [...]/gcc/config/initfini-array.h

..., so let's clarify i686-symbolics-gnu to i686-gnu.

	contrib/
	* config-list.mk (LIST): Clarify i686-symbolics-gnu to i686-gnu.

PR analyzer/108830 reports a situation in which there are lots of
followup -Wanalyzer-null-dereference warnings after the first access of
a NULL pointer, leading to very noisy output from -fanalyzer.

The analyzer's logic for stopping emitting multiple warnings from a
state machine doesn't quite work for NULL pointers: it attempts to
transition the malloc state machine's NULL pointer to the "stop" state,
which doesn't seem to make much sense in retrospect, and seems to get
confused over types.

Similarly, poisoned_value_diagnostic can be very noisy for uninit
variables, emitting a warning for every access to an uninitialized
variable.  In theory, region_model::check_for_poison makes some attempts
to suppress followups, but only for the symbolic value itself; if the
user's code keeps accessing the same region, we would get a warning on
each one.  For example, this showed up in Doom's s_sound.c where there
were 7 followup uninit warnings after the first uninit warning in
"S_ChangeMusic".

This patch adds an extra mechanism, giving pending diagnostics the
option of stopping the analysis of an execution path if they're saved
for emission on it, and turning this on for these warnings:
  -Wanalyzer-null-dereference
  -Wanalyzer-null-argument
  -Wanalyzer-use-after-free
  -Wanalyzer-use-of-pointer-in-stale-stack-frame
  -Wanalyzer-use-of-uninitialized-value

Doing so should hopefully reduce the cascades of diagnostics that
-fanalyzer can sometimes emit.

I added a -fno-analyzer-suppress-followups for the cases where you
really want the followup warnings (e.g. in some DejaGnu tests, and
for microbenchmarks of UB detection, such as PR analyzer/104224).

Integration testing shows this patch reduces the number of probable
false positives reported by 94, and finds one more true positive:

Comparison: 9.34% -> 10.91%
  GOOD:  66 ->  67  (+1)
   BAD: 641 -> 547 (-94)

where the affected warnings/projects are:

  -Wanalyzer-null-dereference: 0.00% GOOD: 0 BAD: 269 -> 239 (-30)
     Unclassified: 257 -> 228 (-29)
                  apr-1.7.0:  12 ->   5  (-7)
                       doom:   1 ->   0  (-1)
              haproxy-2.7.1:  47 ->  41  (-6)
       ImageMagick-7.1.0-57:  13 ->   9  (-4)
                 qemu-7.2.0: 165 -> 154 (-11)

      Known false: 7 -> 6 (-1)
                   xz-5.4.0:   4 ->   3  (-1)

  -Wanalyzer-use-of-uninitialized-value: 0.00% GOOD: 0 BAD: 143 -> 80 (-63)
      Known false: 47 -> 16 (-31)
                       doom: 42 -> 11 (-31)

     Unclassified: 96 -> 64 (-32)
              coreutils-9.1: 14 -> 10  (-4)
              haproxy-2.7.1: 29 -> 23  (-6)
                 qemu-7.2.0: 48 -> 26 (-22)

  -Wanalyzer-null-argument: 0.00% -> 2.33% GOOD: 0 -> 1 (+1) BAD: 43 -> 42 (-1)
     Unclassified: 39 -> 38 (-1)
      due to coreutils-9.1: 9 -> 8 (-1)

    True positive: 0 -> 1 (+1)
      (in haproxy-2.7.1)

gcc/analyzer/ChangeLog:
	PR analyzer/108830
	* analyzer.opt (fanalyzer-suppress-followups): New option.
	* engine.cc (impl_region_model_context::warn): Terminate the path
	if the diagnostic's terminate_path_p vfunc returns true and
	-fanalyzer-suppress-followups is true (the default).
	(impl_sm_context::warn): Likewise, for both overloads.
	* pending-diagnostic.h (pending_diagnostic::terminate_path_p): New
	vfunc.
	* program-state.cc (program_state::on_edge): Terminate the path if
	the ctxt requests it during updating the edge.
	* region-model.cc (poisoned_value_diagnostic::terminate_path_p):
	New vfunc.
	* sm-malloc.cc (null_deref::terminate_path_p): New vfunc.
	(null_arg::terminate_path_p): New vfunc.

gcc/ChangeLog:
	PR analyzer/108830
	* doc/invoke.texi: Document -fno-analyzer-suppress-followups.

gcc/testsuite/ChangeLog:
	PR analyzer/108830
	* gcc.dg/analyzer/attribute-nonnull.c: Update for
	-Wanalyzer-use-of-uninitialized-value terminating analysis along
	a path.
	* gcc.dg/analyzer/call-summaries-2.c: Likewise.
	* gcc.dg/analyzer/data-model-1.c: Likewise.
	* gcc.dg/analyzer/data-model-5.c: Likewise.
	* gcc.dg/analyzer/doom-s_sound-pr108867.c: New test.
	* gcc.dg/analyzer/memset-CVE-2017-18549-1.c: Add
	-fno-analyzer-suppress-followups.
	* gcc.dg/analyzer/null-deref-pr108830.c: New test.
	* gcc.dg/analyzer/pipe-1.c: Add -fno-analyzer-suppress-followups.
	* gcc.dg/analyzer/pipe-void-return.c: Likewise.
	* gcc.dg/analyzer/pipe2-1.c: Likewise.
	* gcc.dg/analyzer/pr101547.c: Update for
	-Wanalyzer-use-of-uninitialized-value terminating analysis along
	a path.
	* gcc.dg/analyzer/pr101875.c: Likewise.
	* gcc.dg/analyzer/pr104224-split.c: New test, based on...
	* gcc.dg/analyzer/pr104224.c: Add
	-fno-analyzer-suppress-followups.
	* gcc.dg/analyzer/realloc-2.c: Add
	-fno-analyzer-suppress-followups.
	* gcc.dg/analyzer/realloc-3.c: Likewise.
	* gcc.dg/analyzer/realloc-5.c: Likewise.
	* gcc.dg/analyzer/stdarg-1-ms_abi.c: Likewise.
	* gcc.dg/analyzer/stdarg-1-sysv_abi.c: Likewise.
	* gcc.dg/analyzer/stdarg-1.c: Likewise.
	* gcc.dg/analyzer/symbolic-1.c: Likewise.
	* gcc.dg/analyzer/symbolic-7.c: Update for
	-Wanalyzer-use-of-uninitialized-value terminating analysis along a
	path.
	* gcc.dg/analyzer/uninit-4.c: Likewise.
	* gcc.dg/analyzer/uninit-8.c: New test.
	* gcc.dg/analyzer/uninit-pr94713.c: Update for
	-Wanalyzer-use-of-uninitialized-value terminating analysis along a
	path.
	* gcc.dg/analyzer/zlib-6a.c: Add -fno-analyzer-suppress-followups.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>

gcc/
	PR target/108876
	* config/xtensa/xtensa.cc (xtensa_expand_epilogue): Drop emit_use
	for A0_REG.
	* config/xtensa/xtensa.md (sibcall, sibcall_internal)
	(sibcall_value, sibcall_value_internal): Add 'use' expression
	for A0_REG.

gcc/fortran/ChangeLog:

	PR fortran/96025
	* parse.cc (check_function_result_typed): Improve type check of
	specification expression for character length and return status.
	(parse_spec): Use status from above.
	* resolve.cc (resolve_fntype): Prevent use of invalid specification
	expression for character length.

gcc/testsuite/ChangeLog:

	PR fortran/96025
	* gfortran.dg/pr96025.f90: New test.

Phobos changes:

    - Unicode tables have been updated to version 15.

libphobos/ChangeLog:

	* src/MERGE: Merge upstream phobos e5a521ab2.

D front-end changes:

	- Import dmd v2.102.0-beta.1
	- `static assert' now supports multiple message arguments.

D runtime changes:

	- Import druntime v2.102.0-beta.1
	- The default `Throwable.TraceInfo' generation now is `@nogc'.
	- `Object.factory' method has now been deprecated.

Phobos changes:

	- Import phobos v2.102.0-beta.1
	- Added float- and double-precision implementations for log
	  function families in std.math.
	- `std.typecons.Unique' now calls `destroy` on struct types

gcc/d/ChangeLog:

	* Make-lang.in (D_FRONTEND_OBJS): Add d/location.o.
	* d-lang.cc (d_init_options): Update for new front-end interface.
	(d_post_options): Call Loc::set after handling options.
	* dmd/MERGE: Merge upstream dmd 09faa4eacd.
	* dmd/VERSION: Bump version to v2.102.0-beta.1.

libphobos/ChangeLog:

	* libdruntime/MERGE: Merge upstream druntime 09faa4eacd.
	* src/MERGE: Merge upstream phobos 13ef27a56.
	* testsuite/libphobos.exceptions/refcounted.d: Add test for chained
	reference counted exceptions.
	* testsuite/libphobos.shared/finalize.d: Add dg-warning for deprecated
	factory interfaces.
	* testsuite/libphobos.gc/issue22843.d: New test.

gcc/testsuite/ChangeLog:

	* gdc.dg/simd2a.d: Update.
	* gdc.dg/simd2b.d: Update.
	* gdc.dg/simd2c.d: Update.
	* gdc.dg/simd2d.d: Update.
	* gdc.dg/simd2e.d: Update.
	* gdc.dg/simd2f.d: Update.
	* gdc.dg/simd2g.d: Update.
	* gdc.dg/simd2h.d: Update.
	* gdc.dg/simd2i.d: Update.
	* gdc.dg/simd2j.d: Update.

Removes an unnecessary rewriting of the front-end AST during lowering.

gcc/d/ChangeLog:

	* d-codegen.cc (d_build_call): Remove front-end expansion of
	side-effects in a call expression.
	* d-gimplify.cc (d_gimplify_call_expr): Gimplify the callee before its
	arguments.

As functions which have semantic analysis ran late may still require
the use of CTFE built-ins to be evaluated.

gcc/d/ChangeLog:

	* decl.cc (DeclVisitor::visit (FuncDeclaration *)): Set
	doing_semantic_analysis_p before calling functionSemantic3.

gcc/testsuite/ChangeLog:

	* gdc.dg/ctfeintrinsics.d: New test.

libphobos/ChangeLog:

	* libdruntime/gcc/backtrace.d (simpleErrorCallback): Add @nogc.
	(LibBacktrace.initLibBacktrace): Likewise.
	(LibBacktrace.this): Likewise.
	(UnwindBacktrace.this): Likewise.
	(getBacktrace): Likewise.
	(getBacktraceSymbols): Likewise.
	* libdruntime/gcc/libbacktrace.d.in (backtrace_create_state):
	Likewise.
	(backtrace_full): Likewise.
	(backtrace_simple): Likewise.
	(backtrace_print): Likewise.
	(backtrace_pcinfo): Likewise.
	(backtrace_syminfo): Likewise.

The following gets rid of the idea that we should prevent setjmp
like calls from popping up in uncontrolled way in the IL for now.
The solution is probably to handle it similar as noreturn has
the ctrl-altering flag on stmts, but use another flag, for example
ctrl-receiving which would also make sure the stmt is first.

	PR tree-optimization/108691
	* tree-ssa-dce.cc (eliminate_unnecessary_stmts): Remove
	assert about calls_setjmp not becoming true when it was false.

	* gcc.dg/pr108691.c: New testcase.

When computing the number of iterations until wrap types are mixed up,
eventually leading to checking ICEs with a pointer bitwise inversion.
The following uses niter_type for the calculation.

	PR tree-optimization/108793
	* tree-ssa-loop-niter.cc (number_of_iterations_until_wrap):
	Use convert operands to niter_type when computing num.

	* gcc.dg/torture/pr108793.c: New testcase.

... which accidentally had gotten reverted in recent
commit r13-6156-g1e8eb102200902e12c1b00e867e338be0a92c292
"gccrs: dump: Emit visibility when dumping items".

gcc/rust/ChangeLog:

	* backend/rust-builtins.cc (BuiltinsContext::setup_math_fns): New functions.

gcc/testsuite/ChangeLog:

	* rust/compile/torture/intrinsics-math.rs: New test.

We only used one path of the C++ folder's get_nth_callarg function:
CALL_EXPR_ARG. Replace all calls to get_nth_callarg by macro calls to
CALL_EXPR_ARG

gcc/rust/ChangeLog:

	* backend/rust-constexpr.cc (get_nth_callarg): Remove function.
	(rs_bind_parameters_in_call): Use CALL_EXPR_ARG instead.
	(potential_constant_expression_1): Likewise.

... lost in #1527 commit 138a6260124740208b8f3aff2e38617f43b05fe8
"rust: Add -frust-compile-until option".

gcc/rust/ChangeLog:

	* lang.opt: Fix ordering of file.

gcc/rust/ChangeLog:

	* backend/rust-compile-type.cc (TyTyResolveCompile::visit): Remove unused parameters.
	* backend/rust-constexpr.cc (constant_value_1): Likewise.
	(fold_non_dependent_init): Likewise.
	* backend/rust-tree.cc (publicly_uniquely_derived_p): Likewise.
	(instantiation_dependent_expression_p): Likewise.
	(type_has_nontrivial_copy_init): Likewise.
	(is_normal_capture_proxy): Likewise.
	(resolve_nondeduced_context): Likewise.
	(undeduced_auto_decl): Likewise.
	(require_deduced_type): Likewise.
	* checks/errors/privacy/rust-privacy-reporter.cc (PrivacyReporter::visit): Likewise.
	* checks/errors/privacy/rust-reachability.cc (ReachabilityVisitor::visit): Likewise.
	* checks/errors/privacy/rust-visibility-resolver.cc (VisibilityResolver::visit): Likewise.
	* checks/errors/rust-const-checker.cc (ConstChecker::visit): Likewise.
	* checks/errors/rust-unsafe-checker.cc (UnsafeChecker::visit): Likewise.
	* checks/lints/rust-lint-marklive.cc (MarkLive::go): Likewise.
	* checks/lints/rust-lint-unused-var.cc (unused_var_walk_fn): Likewise.
	* expand/rust-macro-builtins.cc (try_expand_single_string_literal): Likewise.
	(try_expand_many_expr): Likewise.
	(parse_single_string_literal): Likewise.
	(MacroBuiltin::assert_handler): Likewise.
	(MacroBuiltin::file_handler): Likewise.
	(MacroBuiltin::column_handler): Likewise.
	(MacroBuiltin::concat_handler): Likewise.
	(MacroBuiltin::env_handler): Likewise.
	(MacroBuiltin::line_handler): Likewise.
	* hir/rust-ast-lower-base.cc (ASTLoweringBase::visit): Likewise.
	(ASTLoweringBase::handle_doc_item_attribute): Likewise.
	* hir/rust-hir-dump.cc (Dump::visit): Likewise.
	* hir/tree/rust-hir-full-test.cc (ConstGenericParam::accept_vis): Likewise.
	* lex/rust-lex.cc (Lexer::parse_utf8_escape): Likewise.
	(Lexer::parse_string): Likewise.
	(Lexer::parse_char_or_lifetime): Likewise.
	* lex/rust-lex.h: Likewise.
	* metadata/rust-export-metadata.cc: Likewise.
	* resolve/rust-ast-resolve-expr.cc (ResolveExpr::visit): Likewise.
	* resolve/rust-ast-resolve-type.cc (ResolveType::visit): Likewise.
	(ResolveTypeToCanonicalPath::visit): Likewise.
	* resolve/rust-ast-verify-assignee.h: Likewise.
	* resolve/rust-early-name-resolver.cc (EarlyNameResolver::visit): Likewise.
	* typecheck/rust-hir-type-check-expr.h: Likewise.
	* typecheck/rust-hir-type-check-item.h: Likewise.
	* typecheck/rust-hir-type-check-pattern.cc (TypeCheckPattern::visit): Likewise.
	* typecheck/rust-tyty-rules.h: Likewise.
	* util/rust-attributes.cc (AttributeChecker::visit): Likewise.

gccrs: Skip this debug test case which is failing on the latest mac-os devtools and its only for debug info

gcc/testsuite/ChangeLog:

	* rust/debug/chartype.rs: Skip testcases on Darwin architectures.

This adds missing copy constructors to HIR::PathExprSegment which were
wrongly defaulting to empty vectors when apply specified generic arguments
to method calls.

gcc/rust/ChangeLog:

	* hir/tree/rust-hir-expr.h: Add const `get_method_name`.
	* hir/tree/rust-hir-full-decls.h (struct GenericArgs): Move from `struct`...
	(class GenericArgs): ...to `class`.
	* hir/tree/rust-hir-path.h (struct GenericArgs): Likewise.
	(class GenericArgs): Clear `type_args` in copy constructor.
	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit): Reorder
	debug print.
	* typecheck/rust-tyty.h: Add default constructors for `SubstitutionArgumentMappings`.

When we have a closure expression that captures a parent function's
variable we must setup the closure data to contain this. Ignoring
moveability and mutability requires for now, this patch creates the closure
structure with fields for each of the captured variables. When it comes to
compilation of the closure expression in order to support nested closures
we must setup a context of implicit mappings so that for all path
resolution we hit this implicit closure mappings lookups code before any
lookup_var_decl as this decl will not exist so the order here is important
during path resolution which is a similar problem to match expression
destructuring.

Fixes #195

gcc/rust/ChangeLog:

	* backend/rust-compile-context.cc (Context::push_closure_context): New function.
	(Context::pop_closure_context): Likewise.
	(Context::insert_closure_binding): Likewise.
	(Context::lookup_closure_binding): Likewise.
	* backend/rust-compile-context.h: Declare new functions and closure mappings.
	* backend/rust-compile-expr.cc (CompileExpr::visit): Visit captures properly.
	(CompileExpr::generate_closure_function): Compile captures properly.
	* backend/rust-compile-resolve-path.cc (ResolvePathRef::resolve): Check for
	closure bindings.
	* backend/rust-compile-type.cc (TyTyResolveCompile::visit): Compile capture list's
	types as well.

gcc/testsuite/ChangeLog:

	* rust/execute/torture/closure3.rs: New test.

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit): Pass captures
	properly to `TyTy::ClosureType` constructor.
	* typecheck/rust-tyty.cc (ClosureType::as_string): Fix string representation.
	(ClosureType::clone): Pass `captures` argument.
	* typecheck/rust-tyty.h: Add `captures` field.

When we have a closure block referencing variables in a parent function,
we must track what these are. We do this by having a context of closures
so if we have a variable reference and its declared in a rib whose node id
is less than the node id of the closure's node id we know it must be a
captured variable. We also need to iterate all possible closure contexts
as we might be in the case of a nested closure.

Addresses #195

gcc/rust/ChangeLog:

	* resolve/rust-ast-resolve-expr.cc (ResolveExpr::visit): Use proper closure
	contexts.
	* resolve/rust-name-resolver.cc (Scope::lookup_decl_type): New function.
	(Scope::lookup_rib_for_decl): Likewise.
	(Resolver::insert_resolved_name): Insert captured items.
	(Resolver::push_closure_context): New function.
	(Resolver::pop_closure_context): Likewise.
	(Resolver::insert_captured_item): Likewise.
	(Resolver::decl_needs_capture): Likewise.
	(Resolver::get_captures): Likewise.
	* resolve/rust-name-resolver.h: Declare new functions.

This allows us to track the type of declaration that is stored within a
Rib.

gcc/rust/ChangeLog:

	* resolve/rust-ast-resolve-expr.cc (ResolveExpr::visit): Add Rib argument.
	(ResolveExpr::resolve_closure_param): Likewise.
	* resolve/rust-ast-resolve-implitem.h: Likewise.
	* resolve/rust-ast-resolve-item.cc (ResolveTraitItems::visit): Likewise.
	(ResolveItem::visit): Likewise.
	* resolve/rust-ast-resolve-pattern.cc (PatternDeclaration::visit): Likewise.
	* resolve/rust-ast-resolve-pattern.h: Likewise.
	* resolve/rust-ast-resolve-stmt.h: Likewise.
	* resolve/rust-ast-resolve-toplevel.h: Likewise.
	* resolve/rust-ast-resolve-type.h: Likewise.
	* resolve/rust-name-resolver.cc (Rib::lookup_decl_type): Likewise.
	(Scope::insert): Likewise.
	(Resolver::insert_builtin_types): Likewise.
	* resolve/rust-name-resolver.h: Likewise.

This macro is a mess and a helper method is much better for this case.

gcc/rust/ChangeLog:

	* resolve/rust-name-resolver.cc (MKBUILTIN_TYPE): Remove macro.
	(Rib::Rib): Remove `mappings` field.
	(Resolver::generate_builtins): Use `setup_builtin` instead of macro.
	(Resolver::setup_builtin): New function.
	* resolve/rust-name-resolver.h: Declare `setup_builtin`, add FIXME
	comment.

gcc/rust/ChangeLog:

	* lex/rust-lex.cc (Lexer::Lexer): Add `dump_lex` boolean flag.
	(Lexer::skip_token): Dump tokens if flag is enabled.
	(Lexer::dump_and_skip): New function.
	* lex/rust-lex.h: Include optional.h and declare functions.
	* parse/rust-parse-impl.h (Parser::debug_dump_lex_output): Remove old
	unused function.
	* parse/rust-parse.h: Likewise.
	* rust-session-manager.cc (Session::compile_crate): Pass lexer dump
	option to lexer.
	(Session::dump_lex): New function.
	* util/rust-optional.h: Add missing constructor.

Signed-off-by: Raiki Tamura <tamaron1203@gmail.com>

gcc/rust/ChangeLog:

	* ast/rust-item.h: Remoe default location for Visibility class.
	* parse/rust-parse-impl.h (Parser::parse_visibility): Pass proper location
	when instantiating visibilities.

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Fix dumping of fn params.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Remove extraneous string when
	dumping statements.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc: Remove unused include.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.
	* ast/rust-ast-dump.h: Likewise.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

+ Return FunctionQualifiers as ref to work in ast dump

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.
	* ast/rust-ast-dump.h: Add missing getter declaration.
	* ast/rust-ast-full-test.cc (BareFunctionType::as_string): Fix bare function
	string representation.
	* ast/rust-type.h (class BareFunctionType): Declare said getter.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>

gcc/rust/ChangeLog:

	* ast/rust-ast-dump.cc (Dump::visit): Add missing visitor.

Signed-off-by: Jakub Dupak <dev@jakubdupak.com>