Update gnulib to current upstream master

Update gnulib to current upstream master

I tried building gdb with G++ 4.7 and CXX="g++ -std=gnu+11", and that
tripped on a build error:

  In file included from build-gnulib/import/stdio.h:53:0,
		   from /home/pedro/gdb/mygit/cxx-convertion/src/gdb/common/common-defs.h:31,
		   from /home/pedro/gdb/mygit/cxx-convertion/src/gdb/defs.h:28,
		   from /home/pedro/gdb/mygit/cxx-convertion/src/gdb/armobsd-tdep.c:20:
  build-gnulib/import/stddef.h:104:3: error: conflicting declaration ‘typedef union max_align_t max_align_t’
  In file included from build-gnulib/import/stddef.h:55:0,
		   from build-gnulib/import/stdio.h:53,
		   from /home/pedro/gdb/mygit/cxx-convertion/src/gdb/common/common-defs.h:31,
		   from /home/pedro/gdb/mygit/cxx-convertion/src/gdb/defs.h:28,
		   from /home/pedro/gdb/mygit/cxx-convertion/src/gdb/armobsd-tdep.c:20:
  /opt/gcc-4.7/lib/gcc/x86_64-unknown-linux-gnu/4.7.4/include/stddef.h:426:3: error: ‘max_align_t’ has a previous declaration as ‘typedef struct max_align_t max_align_t’

Updating gnulib to current master fixes it, since it brings in this
fix:

 http://lists.gnu.org/archive/html/bug-gnulib/2016-04/msg00000.html

Our last update was in August 2015.  This doesn't bring in much added
baggage, it's mostly bug fixes.  It pulled in the "limits-h" module as
automatic dependency, and given that looks potentially useful I added
it to the set of modules we require.

Tested on x86_64 Fedora 23, with g++ 4.7 and g++ 5.3, native and gdbserver.

gdb/ChangeLog:
2016-10-18  Pedro Alves  <palves@redhat.com>

	* gnulib/update-gnulib.sh (GNULIB_COMMIT_SHA1): Set to
	2692e23a48e21f6daa029e8af9f1a143b7532f47.
	* gnulib/configure, gnulib/config.in, gnulib/aclocal.m4:
	Regenerate.
	* gnulib/import/Makefile: Update.
	* gnulib/import/alloca: Update.
	* gnulib/import/basename-lgpl: Update.
	* gnulib/import/canonicalize-lgpl: Update.
	* gnulib/import/config: Update.
	* gnulib/import/dirent: Update.
	* gnulib/import/dirfd: Update.
	* gnulib/import/dirname-lgpl: Update.
	* gnulib/import/dirname.h: Update.
	* gnulib/import/dosname.h: Update.
	* gnulib/import/errno: Update.
	* gnulib/import/extra/snippet/arg-nonnull.h: Update.
	* gnulib/import/extra/snippet/c++defs.h: Update.
	* gnulib/import/extra/snippet/warn-on-use.h: Update.
	* gnulib/import/extra/update-copyright: Update.
	* gnulib/import/flexmember.h: Update.
	* gnulib/import/float+.h: Update.
	* gnulib/import/float: Update.
	* gnulib/import/float: Update.
	* gnulib/import/fnmatch: Update.
	* gnulib/import/fnmatch: Update.
	* gnulib/import/fnmatch_loop: Update.
	* gnulib/import/fpucw.h: Update.
	* gnulib/import/frexp: Update.
	* gnulib/import/frexpl: Update.
	* gnulib/import/gettimeofday: Update.
	* gnulib/import/hard-locale: Update.
	* gnulib/import/hard-locale.h: Update.
	* gnulib/import/inttypes: Update.
	* gnulib/import/isnan: Update.
	* gnulib/import/isnand-nolibm.h: Update.
	* gnulib/import/isnand: Update.
	* gnulib/import/isnanl-nolibm.h: Update.
	* gnulib/import/isnanl: Update.
	* gnulib/import/itold: Update.
	* gnulib/import/limits: Update.
	* gnulib/import/localcharset: Update.
	* gnulib/import/localcharset.h: Update.
	* gnulib/import/lstat: Update.
	* gnulib/import/m4/00gnulib: Update.
	* gnulib/import/m4/absolute-header: Update.
	* gnulib/import/m4/alloca: Update.
	* gnulib/import/m4/canonicalize: Update.
	* gnulib/import/m4/codeset: Update.
	* gnulib/import/m4/configmake: Update.
	* gnulib/import/m4/dirent_h: Update.
	* gnulib/import/m4/dirfd: Update.
	* gnulib/import/m4/dirname: Update.
	* gnulib/import/m4/double-slash-root: Update.
	* gnulib/import/m4/eealloc: Update.
	* gnulib/import/m4/errno_h: Update.
	* gnulib/import/m4/exponentd: Update.
	* gnulib/import/m4/exponentl: Update.
	* gnulib/import/m4/extensions: Update.
	* gnulib/import/m4/extern-inline: Update.
	* gnulib/import/m4/fcntl-o: Update.
	* gnulib/import/m4/flexmember: Update.
	* gnulib/import/m4/float_h: Update.
	* gnulib/import/m4/fnmatch: Update.
	* gnulib/import/m4/fpieee: Update.
	* gnulib/import/m4/frexp: Update.
	* gnulib/import/m4/frexpl: Update.
	* gnulib/import/m4/gettimeofday: Update.
	* gnulib/import/m4/glibc21: Update.
	* gnulib/import/m4/gnulib-cache: Update.
	* gnulib/import/m4/gnulib-common: Update.
	* gnulib/import/m4/gnulib-comp: Update.
	* gnulib/import/m4/gnulib-tool: Update.
	* gnulib/import/m4/hard-locale: Update.
	* gnulib/import/m4/include_next: Update.
	* gnulib/import/m4/inttypes-pri: Update.
	* gnulib/import/m4/inttypes: Update.
	* gnulib/import/m4/isnand: Update.
	* gnulib/import/m4/isnanl: Update.
	* gnulib/import/m4/largefile: Update.
	* gnulib/import/m4/limits-h: Update.
	* gnulib/import/m4/localcharset: Update.
	* gnulib/import/m4/locale-fr: Update.
	* gnulib/import/m4/locale-ja: Update.
	* gnulib/import/m4/locale-zh: Update.
	* gnulib/import/m4/longlong: Update.
	* gnulib/import/m4/lstat: Update.
	* gnulib/import/m4/malloc: Update.
	* gnulib/import/m4/malloca: Update.
	* gnulib/import/m4/math_h: Update.
	* gnulib/import/m4/mbrtowc: Update.
	* gnulib/import/m4/mbsinit: Update.
	* gnulib/import/m4/mbsrtowcs: Update.
	* gnulib/import/m4/mbstate_t: Update.
	* gnulib/import/m4/memchr: Update.
	* gnulib/import/m4/memmem: Update.
	* gnulib/import/m4/mmap-anon: Update.
	* gnulib/import/m4/multiarch: Update.
	* gnulib/import/m4/nocrash: Update.
	* gnulib/import/m4/off_t: Update.
	* gnulib/import/m4/pathmax: Update.
	* gnulib/import/m4/rawmemchr: Update.
	* gnulib/import/m4/readlink: Update.
	* gnulib/import/m4/rename: Update.
	* gnulib/import/m4/rmdir: Update.
	* gnulib/import/m4/signal_h: Update.
	* gnulib/import/m4/ssize_t: Update.
	* gnulib/import/m4/stat: Update.
	* gnulib/import/m4/stdbool: Update.
	* gnulib/import/m4/stddef_h: Update.
	* gnulib/import/m4/stdint: Update.
	* gnulib/import/m4/stdio_h: Update.
	* gnulib/import/m4/stdlib_h: Update.
	* gnulib/import/m4/strchrnul: Update.
	* gnulib/import/m4/string_h: Update.
	* gnulib/import/m4/strstr: Update.
	* gnulib/import/m4/strtok_r: Update.
	* gnulib/import/m4/sys_socket_h: Update.
	* gnulib/import/m4/sys_stat_h: Update.
	* gnulib/import/m4/sys_time_h: Update.
	* gnulib/import/m4/sys_types_h: Update.
	* gnulib/import/m4/time_h: Update.
	* gnulib/import/m4/unistd_h: Update.
	* gnulib/import/m4/warn-on-use: Update.
	* gnulib/import/m4/wchar_h: Update.
	* gnulib/import/m4/wchar_t: Update.
	* gnulib/import/m4/wctype_h: Update.
	* gnulib/import/m4/wint_t: Update.
	* gnulib/import/malloc: Update.
	* gnulib/import/malloca: Update.
	* gnulib/import/malloca.h: Update.
	* gnulib/import/math: Update.
	* gnulib/import/math: Update.
	* gnulib/import/mbrtowc: Update.
	* gnulib/import/mbsinit: Update.
	* gnulib/import/mbsrtowcs-impl.h: Update.
	* gnulib/import/mbsrtowcs-state: Update.
	* gnulib/import/mbsrtowcs: Update.
	* gnulib/import/memchr: Update.
	* gnulib/import/memmem: Update.
	* gnulib/import/pathmax.h: Update.
	* gnulib/import/rawmemchr: Update.
	* gnulib/import/readlink: Update.
	* gnulib/import/ref-add.sin: Update.
	* gnulib/import/ref-del.sin: Update.
	* gnulib/import/rename: Update.
	* gnulib/import/rmdir: Update.
	* gnulib/import/same-inode.h: Update.
	* gnulib/import/signal: Update.
	* gnulib/import/stat: Update.
	* gnulib/import/stdbool: Update.
	* gnulib/import/stddef: Update.
	* gnulib/import/stdint: Update.
	* gnulib/import/stdio: Update.
	* gnulib/import/stdlib: Update.
	* gnulib/import/str-two-way.h: Update.
	* gnulib/import/strchrnul: Update.
	* gnulib/import/streq.h: Update.
	* gnulib/import/string: Update.
	* gnulib/import/stripslash: Update.
	* gnulib/import/strnlen1: Update.
	* gnulib/import/strnlen1.h: Update.
	* gnulib/import/strstr: Update.
	* gnulib/import/strtok_r: Update.
	* gnulib/import/sys_stat: Update.
	* gnulib/import/sys_time: Update.
	* gnulib/import/sys_types: Update.
	* gnulib/import/time: Update.
	* gnulib/import/unistd: Update.
	* gnulib/import/unistd: Update.
	* gnulib/import/verify.h: Update.
	* gnulib/import/wchar: Update.
	* gnulib/import/wctype: Update.
	* gnulib/import/flexmember.h: New file.
	* gnulib/import/hard-locale.c: New file.
	* gnulib/import/hard-locale.h: New file.
	* gnulib/import/limits.in.h: New file.
	* gnulib/import/m4/flexmember.m4: New file.
	* gnulib/import/m4/hard-locale.m4: New file.
	* gnulib/import/m4/limits-h.m4: New file.