Problem reported by Joseph Myers in:
https://gcc.gnu.org/ml/gcc-patches/2016-09/msg00340.html
* doc/posix-headers/stdalign.texi: Do not imply that C11 prohibits
alignof(S) where S is a structure containing a flexible array
member. The Gnulib substitute does not support this, but C11 does.
* doc/posix-headers/stdalign.texi (stdalign.h):
Document the C11 restriction.
* lib/fts.c: Include stddef.h, for max_align_t.
(fts_alloc): Align using max_align_t, not FTSENT.
* modules/fts (Depends-on): Add stddef.
ISO C11 says that _Alignof's operand must be a parenthesized type.
Problem reported by Eli Zaretskii in
<http://lists.gnu.org/archive/html/emacs-devel/2013-03/msg00960.html>.
* doc/posix-headers/stdalign.texi (stdalign.h): Document this.
* m4/stdalign.m4 (gl_STDALIGN_H): Don't use _Alignof (expr).
Problem reported by Simon Josefsson in
<http://lists.gnu.org/archive/html/bug-gnulib/2011-12/msg00005.html>.
* doc/posix-headers/stdalign.texi (stdalign.h): Mention Clang 3.0,
which has <stdalign.h> but which does not define alignof.
* m4/stdalign.m4 (gl_STDALIGN_H): Check for Clang 3.0's problem.
I think these problems were reported by Bruno Haible, in email
that I've unfortunately misplaced.
* doc/posix-headers/stdalign.texi (stdalign.h): Document more
shortcomings of MSVC and of Sun C 5.11.
* lib/stdalign.in.h (_Alignas): Omit bogus extra parenthesis
around __declspec arg.
* modules/stdalign-tests (Files): Add tests/macros.h.
* tests/test-stdalign.c: Do not include <stdlib.h>; no longer needed.
Include macros.h, for ASSERT.
(DECLARE_ALIGNED): Remove.
(TEST_ALIGNMENT): Define to 16 if alignment is supported (more likely
to catch bug), and to 1 if not (simplifies the rest of the code).
(CHECK_STATIC): Always declare the alignment test vars; that's simpler.
(CHECK_AUTO): Remove.
(CHECK_ALIGNED): Check only the alignment of the static vars,
since auto var alignment isn't supported by Sun C 5.11.
(CHECK_TYPES): Remove. All uses replaced by inline code, so that
ASSERT failures are easier to diagnose.
