Support exception propagation without lock-free atomic int

2017-01-04  Pauli Nieminen  <suokkos@gmail.com>
	    Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/64735
	* acinclude.m4 (GLIBCXX_CHECK_EXCEPTION_PTR_SYMVER): Define.
	* config.h.in: Regenerate.
	* config/abi/pre/gnu.ver [HAVE_EXCEPTION_PTR_SINCE_GCC46]
	(GLIBCXX_3.4.15, GLIBCXX_3.4.21, CXXABI_1.3.3, CXXABI_1.3.5): Make
	exports for exception_ptr, nested_exception, and future conditional.
	[HAVE_EXCEPTION_PTR_SINCE_GCC46] (GLIBCXX_3.4.23, CXXABI_1.3.11): Add
	exports for exception_ptr, nested_exception, and future conditional.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_CHECK_EXCEPTION_PTR_SYMVER.
	* include/std/future: Remove check for ATOMIC_INT_LOCK_FREE
	* libsupc++/eh_atomics.h: New file for internal use only.
	(__eh_atomic_inc, __eh_atomic_dec): New.
	* libsupc++/eh_ptr.cc (exception_ptr::_M_addref)
	(exception_ptr::_M_release) (__gxx_dependent_exception_cleanup)
	(rethrow_exception): Use eh_atomics.h reference counting helpers.
	* libsupc++/eh_throw.cc (__gxx_exception_cleanup): Likewise.
	* libsupc++/eh_tm.cc (free_any_cxa_exception): Likewise.
	* libsupc++/exception: Remove check for ATOMIC_INT_LOCK_FREE.
	* libsupc++/exception_ptr.h: Likewise.
	* libsupc++/guard.cc: Include header for ATOMIC_INT_LOCK_FREE macro.
	* libsupc++/nested_exception.cc: Remove check for
	ATOMIC_INT_LOCK_FREE.
	* libsupc++/nested_exception.h: Likewise.
	* src/c++11/future.cc: Likewise.
	* testsuite/18_support/exception_ptr/*: Remove atomic builtins checks.
	* testsuite/18_support/nested_exception/*: Likewise.
	* testsuite/30_threads/async/*: Likewise.
	* testsuite/30_threads/future/*: Likewise.
	* testsuite/30_threads/headers/future/types_std_c++0x.cc: Likewise.
	* testsuite/30_threads/packaged_task/*: Likewise.
	* testsuite/30_threads/promise/*: Likewise.
	* testsuite/30_threads/shared_future/*: Likewise.

Co-Authored-By: Jonathan Wakely <jwakely@redhat.com>

From-SVN: r244051