This is minor refactoring that should not affect Emacs builds.
It incorporates:
2018-10-12 Make better use of Autoconf
* m4/environ.m4, m4/fsusage.m4, m4/manywarnings.m4, m4/socklen.m4:
Copy from Gnulib.
This incorporates:
2018-01-01 maint: Run 'make update-copyright'
2017-12-29 Add cross-compilation results for GNU/Hurd.
2017-12-12 explicit_bzero: port to macOS + Clang 9.0.0
* .bzrignore: Add lib/stdalign.h.
* config.bat: Do not set NO_DECL_ALIGN; no longer needed.
Copy lib/stdalign.in.h to lib/stdalign.in-h as needed.
* configure.ac (HAVE_ATTRIBUTE_ALIGNED): Remove the code that
fiddles with this, as gnulib now does this for us.
* admin/merge-gnulib: Add environ, stdalign.
* m4/environ.m4: New file, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/stdalign.in.h, m4/stdalign.m4: New files, from gnulib.
* sed2v2.inp (HAVE_ATTRIBUTE_ALIGNED): Remove edit.
* sedlibmk.inp (STDALIGN_H, @GL_GENERATE_STDALIGN_H_TRUE@)
(GL_GENERATE_STDALIGN_H_FALSE): New edits.
* nt/config.nt (HAVE_ATTRIBUTE_ALIGNED): Remove.
* src/alloc.c (XMALLOC_BASE_ALIGNMENT, GC_POINTER_ALIGNMENT, pure_alloc):
Simplify by using alignof.
(pure_alloc) [! USE_LSB_TAG]: Don't over-align EMACS_INT values.
* src/lisp.h: Include <stdalign.h>.
(GCALIGNMENT): New macro and constant.
(DECL_ALIGN): Remove. All uses replaced by alignas (GCALIGNMENT).
(USE_LSB_TAG): ifdef on alignas, not on DECL_ALIGN.
(stdalign): New macro, if not already defined.
