Add out-of-line versions of some <stdatomic.h> functions (PR c/65083)

[Jeff Law]

On 11/13/2015 03:15 AM, Joseph Myers wrote:
> PR c/65083 notes that some functions in <stdatomic.h> are normal
> functions, not generic functions, and so need to have out-of-line
> copies that can be called when macro expansion is suppressed (unlike
> the generic functions where DR#419 makes it undefined if you suppress
> a macro expansion).
>
> This patch adds such out-of-line definitions in libatomic for those
> six functions, at a new LIBATOMIC_1.2 symbol version, as trivial
> wrappers to the <stdatomic.h> macros, along with declarations of those
> functions in <stdatomic.h>.  Tests are added that are based on the
> corresponding tests for the macros, but with parentheses around the
> function names to force the out-of-line functions to be used.
>
> Bootstrapped with no regressions on x86_64-pc-linux-gnu.  OK to
> commit?
>
> gcc:
> 2015-11-13  Joseph Myers  <joseph@codesourcery.com>
>
> 	PR c/65083
> 	* ginclude/stdatomic.h (atomic_thread_fence, atomic_signal_fence)
> 	(atomic_flag_test_and_set, atomic_flag_test_and_set_explicit)
> 	(atomic_flag_clear, atomic_flag_clear_explicit): Declare as
> 	functions before defining as macros.
>
> gcc/testsuite:
> 2015-11-13  Joseph Myers  <joseph@codesourcery.com>
>
> 	PR c/65083
> 	* gcc.dg/atomic/stdatomic-fence-2.c,
> 	gcc.dg/atomic/stdatomic-flag-2.c: New tests.
>
> libatomic:
> 2015-11-13  Joseph Myers  <joseph@codesourcery.com>
>
> 	PR c/65083
> 	* fence.c, flag.c: New files.
> 	* Makefile.am (libatomic_la_SOURCES): Add fence.c and flag.c.
> 	* Makefile.in: Regenerate.
> 	* configure.ac (libtool_VERSION): Change to 3:0:2.
> 	* configure: Regenerate.
> 	* libatomic.map (LIBATOMIC_1.2): New symbol version.
OK.

Thanks,
Jeff