Update gnulib to current upstream master

Update gnulib to current upstream master

It has been a while since we don't update our gnulib copy against
their upstream master branch, so I thought I'd propose this patch.  It
also fixes (at least) one bug reported against GDB:

  https://sourceware.org/bugzilla/show_bug.cgi?id=23558

The problem reported there is about the replacement of 'getcwd' when
cross-compiling GDB.  With our current gnulib copy, the mechanism for
deciding whether to use the system's 'getcwd' or gnulib's version is
too simplistic and pessimistic, so when cross-compiling we always end
up using gnulib's version, which has a limitation: it cannot handle
the situation when the parent directory doesn't have read permissions.

This has been reported against upstream gnulib and the fix has been
pushed here:

  https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=a96d2e67052c879b1bcc5bc461722beac75fc372

I regtested this patch on Fedora 28 x86-64, and there were no
regressions.

OK?

gdb/ChangeLog:

2018-08-29  Sergio Durigan Junior  <sergiodj@redhat.com>

	PR gdb/23555
	PR gdb/23558
	* gnulib/aclocal.m4: Regenerate.
	* gnulib/config.in: Regenerate.
	* gnulib/configure: Regenerate.
	* gnulib/import/Makefile.am: Update.
	* gnulib/import/Makefile.in: Update.
	* gnulib/import/extra/snippet/_Noreturn.h: Rename to...
	* gnulib/import/_Noreturn.h: ... this.
	* gnulib/import/alloca.in.h: Update.
	* gnulib/import/extra/snippet/arg-nonnull.h: Rename to...
	* gnulib/import/arg-nonnull.h: ... this.
	* gnulib/import/assure.h: Update.
	* gnulib/import/at-func.c: Update.
	* gnulib/import/basename-lgpl.c: Update.
	* gnulib/import/extra/snippet/c++defs.h: Rename to...
	* gnulib/import/c++defs.h: ... this.
	* gnulib/import/canonicalize-lgpl.c: Update.
	* gnulib/import/cdefs.h: Update.
	* gnulib/import/chdir-long.c: Update.
	* gnulib/import/chdir-long.h: Update.
	* gnulib/import/cloexec.c: Update.
	* gnulib/import/cloexec.h: Update.
	* gnulib/import/close.c: Update.
	* gnulib/import/closedir.c: Update.
	* gnulib/import/config.charset: Update.
	* gnulib/import/dirent-private.h: Update.
	* gnulib/import/dirent.in.h: Update.
	* gnulib/import/dirfd.c: Update.
	* gnulib/import/dirname-lgpl.c: Update.
	* gnulib/import/dirname.h: Update.
	* gnulib/import/dosname.h: Update.
	* gnulib/import/dup-safer-flag.c: Update.
	* gnulib/import/dup-safer.c: Update.
	* gnulib/import/dup.c: Update.
	* gnulib/import/dup2.c: Update.
	* gnulib/import/errno.in.h: Update.
	* gnulib/import/error.c: Update.
	* gnulib/import/error.h: Update.
	* gnulib/import/exitfail.c: Update.
	* gnulib/import/exitfail.h: Update.
	* gnulib/import/extra/update-copyright: Update.
	* gnulib/import/fchdir.c: Update.
	* gnulib/import/fcntl.c: Update.
	* gnulib/import/fcntl.in.h: Update.
	* gnulib/import/fd-hook.c: Update.
	* gnulib/import/fd-hook.h: Update.
	* gnulib/import/fd-safer-flag.c: Update.
	* gnulib/import/fd-safer.c: Update.
	* gnulib/import/fdopendir.c: Update.
	* gnulib/import/filename.h: Update.
	* gnulib/import/filenamecat-lgpl.c: Update.
	* gnulib/import/filenamecat.h: Update.
	* gnulib/import/flexmember.h: Update.
	* gnulib/import/float+.h: Update.
	* gnulib/import/float.c: Update.
	* gnulib/import/float.in.h: Update.
	* gnulib/import/fnmatch.c: Update.
	* gnulib/import/fnmatch.in.h: Update.
	* gnulib/import/fnmatch_loop.c: Update.
	* gnulib/import/fpucw.h: Update.
	* gnulib/import/frexp.c: Update.
	* gnulib/import/frexpl.c: Update.
	* gnulib/import/fstat.c: Update.
	* gnulib/import/fstatat.c: Update.
	* gnulib/import/getcwd-lgpl.c: Update.
	* gnulib/import/getcwd.c: Update.
	* gnulib/import/getdtablesize.c: Update.
	* gnulib/import/getlogin_r.c: Update.
	* gnulib/import/getprogname.c: Update.
	* gnulib/import/getprogname.h: Update.
	* gnulib/import/gettext.h: Update.
	* gnulib/import/gettimeofday.c: Update.
	* gnulib/import/glob-libc.h: Update.
	* gnulib/import/glob.c: Update.
	* gnulib/import/glob.in.h: Update.
	* gnulib/import/glob_internal.h: Update.
	* gnulib/import/glob_pattern_p.c: Update.
	* gnulib/import/globfree.c: Update.
	* gnulib/import/hard-locale.c: Update.
	* gnulib/import/hard-locale.h: Update.
	* gnulib/import/intprops.h: Update.
	* gnulib/import/inttypes.in.h: Update.
	* gnulib/import/isnan.c: Update.
	* gnulib/import/isnand-nolibm.h: Update.
	* gnulib/import/isnand.c: Update.
	* gnulib/import/isnanl-nolibm.h: Update.
	* gnulib/import/isnanl.c: Update.
	* gnulib/import/itold.c: Update.
	* gnulib/import/libc-config.h: Update.
	* gnulib/import/limits.in.h: Update.
	* gnulib/import/localcharset.c: Update.
	* gnulib/import/localcharset.h: Update.
	* gnulib/import/localtime-buffer.c: Update.
	* gnulib/import/localtime-buffer.h: Update.
	* gnulib/import/lstat.c: Update.
	* gnulib/import/m4/00gnulib.m4: Update.
	* gnulib/import/m4/__inline.m4: Update.
	* gnulib/import/m4/absolute-header.m4: Update.
	* gnulib/import/m4/alloca.m4: Update.
	* gnulib/import/m4/builtin-expect.m4: Update.
	* gnulib/import/m4/canonicalize.m4: Update.
	* gnulib/import/m4/chdir-long.m4: Update.
	* gnulib/import/m4/close.m4: Update.
	* gnulib/import/m4/closedir.m4: Update.
	* gnulib/import/m4/configmake.m4: Update.
	* gnulib/import/m4/d-ino.m4: Update.
	* gnulib/import/m4/d-type.m4: Update.
	* gnulib/import/m4/dirent_h.m4: Update.
	* gnulib/import/m4/dirfd.m4: Update.
	* gnulib/import/m4/dirname.m4: Update.
	* gnulib/import/m4/double-slash-root.m4: Update.
	* gnulib/import/m4/dup.m4: Update.
	* gnulib/import/m4/dup2.m4: Update.
	* gnulib/import/m4/eealloc.m4: Update.
	* gnulib/import/m4/environ.m4: Update.
	* gnulib/import/m4/errno_h.m4: Update.
	* gnulib/import/m4/error.m4: Update.
	* gnulib/import/m4/exponentd.m4: Update.
	* gnulib/import/m4/exponentl.m4: Update.
	* gnulib/import/m4/extensions.m4: Update.
	* gnulib/import/m4/extern-inline.m4: Update.
	* gnulib/import/m4/fchdir.m4: Update.
	* gnulib/import/m4/fcntl-o.m4: Update.
	* gnulib/import/m4/fcntl.m4: Update.
	* gnulib/import/m4/fcntl_h.m4: Update.
	* gnulib/import/m4/fdopendir.m4: Update.
	* gnulib/import/m4/filenamecat.m4: Update.
	* gnulib/import/m4/flexmember.m4: Update.
	* gnulib/import/m4/float_h.m4: Update.
	* gnulib/import/m4/fnmatch.m4: Update.
	* gnulib/import/m4/fnmatch_h.m4: Update.
	* gnulib/import/m4/fpieee.m4: Update.
	* gnulib/import/m4/frexp.m4: Update.
	* gnulib/import/m4/frexpl.m4: Update.
	* gnulib/import/m4/fstat.m4: Update.
	* gnulib/import/m4/fstatat.m4: Update.
	* gnulib/import/m4/getcwd-abort-bug.m4: Update.
	* gnulib/import/m4/getcwd-path-max.m4: Update.
	* gnulib/import/m4/getcwd.m4: Update.
	* gnulib/import/m4/getdtablesize.m4: Update.
	* gnulib/import/m4/getlogin.m4: Update.
	* gnulib/import/m4/getlogin_r.m4: Update.
	* gnulib/import/m4/getpagesize.m4: Update.
	* gnulib/import/m4/getprogname.m4: Update.
	* gnulib/import/m4/gettimeofday.m4: Update.
	* gnulib/import/m4/glibc21.m4: Update.
	* gnulib/import/m4/glob.m4: Update.
	* gnulib/import/m4/glob_h.m4: Update.
	* gnulib/import/m4/gnulib-cache.m4: Update.
	* gnulib/import/m4/gnulib-common.m4: Update.
	* gnulib/import/m4/gnulib-comp.m4: Update.
	* gnulib/import/m4/gnulib-tool.m4: Update.
	* gnulib/import/m4/hard-locale.m4: Update.
	* gnulib/import/m4/include_next.m4: Update.
	* gnulib/import/m4/inttypes-pri.m4: Update.
	* gnulib/import/m4/inttypes.m4: Update.
	* gnulib/import/m4/isnand.m4: Update.
	* gnulib/import/m4/isnanl.m4: Update.
	* gnulib/import/m4/largefile.m4: Update.
	* gnulib/import/m4/limits-h.m4: Update.
	* gnulib/import/m4/localcharset.m4: Update.
	* gnulib/import/m4/locale-fr.m4: Update.
	* gnulib/import/m4/locale-ja.m4: Update.
	* gnulib/import/m4/locale-zh.m4: Update.
	* gnulib/import/m4/localtime-buffer.m4: Update.
	* gnulib/import/m4/longlong.m4: Update.
	* gnulib/import/m4/lstat.m4: Update.
	* gnulib/import/m4/malloc.m4: Update.
	* gnulib/import/m4/malloca.m4: Update.
	* gnulib/import/m4/math_h.m4: Update.
	* gnulib/import/m4/mbrtowc.m4: Update.
	* gnulib/import/m4/mbsinit.m4: Update.
	* gnulib/import/m4/mbsrtowcs.m4: Update.
	* gnulib/import/m4/mbstate_t.m4: Update.
	* gnulib/import/m4/memchr.m4: Update.
	* gnulib/import/m4/memmem.m4: Update.
	* gnulib/import/m4/mempcpy.m4: Update.
	* gnulib/import/m4/memrchr.m4: Update.
	* gnulib/import/m4/mkdir.m4: Update.
	* gnulib/import/m4/mkstemp.m4: Update.
	* gnulib/import/m4/mmap-anon.m4: Update.
	* gnulib/import/m4/mode_t.m4: Update.
	* gnulib/import/m4/msvc-inval.m4: Update.
	* gnulib/import/m4/msvc-nothrow.m4: Update.
	* gnulib/import/m4/multiarch.m4: Update.
	* gnulib/import/m4/nocrash.m4: Update.
	* gnulib/import/m4/off_t.m4: Update.
	* gnulib/import/m4/onceonly.m4: Update.
	* gnulib/import/m4/open-cloexec.m4: Update.
	* gnulib/import/m4/open.m4: Update.
	* gnulib/import/m4/openat.m4: Update.
	* gnulib/import/m4/opendir.m4: Update.
	* gnulib/import/m4/pathmax.m4: Update.
	* gnulib/import/m4/rawmemchr.m4: Update.
	* gnulib/import/m4/readdir.m4: Update.
	* gnulib/import/m4/readlink.m4: Update.
	* gnulib/import/m4/realloc.m4: Update.
	* gnulib/import/m4/rename.m4: Update.
	* gnulib/import/m4/rewinddir.m4: Update.
	* gnulib/import/m4/rmdir.m4: Update.
	* gnulib/import/m4/save-cwd.m4: Update.
	* gnulib/import/m4/secure_getenv.m4: Update.
	* gnulib/import/m4/setenv.m4: Update.
	* gnulib/import/m4/signal_h.m4: Update.
	* gnulib/import/m4/ssize_t.m4: Update.
	* gnulib/import/m4/stat-time.m4: Update.
	* gnulib/import/m4/stat.m4: Update.
	* gnulib/import/m4/std-gnu11.m4: Update.
	* gnulib/import/m4/stdbool.m4: Update.
	* gnulib/import/m4/stddef_h.m4: Update.
	* gnulib/import/m4/stdint.m4: Update.
	* gnulib/import/m4/stdio_h.m4: Update.
	* gnulib/import/m4/stdlib_h.m4: Update.
	* gnulib/import/m4/strchrnul.m4: Update.
	* gnulib/import/m4/strdup.m4: Update.
	* gnulib/import/m4/strerror.m4: Update.
	* gnulib/import/m4/string_h.m4: Update.
	* gnulib/import/m4/strstr.m4: Update.
	* gnulib/import/m4/strtok_r.m4: Update.
	* gnulib/import/m4/sys_socket_h.m4: Update.
	* gnulib/import/m4/sys_stat_h.m4: Update.
	* gnulib/import/m4/sys_time_h.m4: Update.
	* gnulib/import/m4/sys_types_h.m4: Update.
	* gnulib/import/m4/tempname.m4: Update.
	* gnulib/import/m4/time_h.m4: Update.
	* gnulib/import/m4/unistd-safer.m4: Update.
	* gnulib/import/m4/unistd_h.m4: Update.
	* gnulib/import/m4/warn-on-use.m4: Update.
	* gnulib/import/m4/wchar_h.m4: Update.
	* gnulib/import/m4/wchar_t.m4: Update.
	* gnulib/import/m4/wctype_h.m4: Update.
	* gnulib/import/m4/wint_t.m4: Update.
	* gnulib/import/malloc.c: Update.
	* gnulib/import/malloc/scratch_buffer.h: Update.
	* gnulib/import/malloc/scratch_buffer_grow.c: Update.
	* gnulib/import/malloc/scratch_buffer_grow_preserve.c: Update.
	* gnulib/import/malloc/scratch_buffer_set_array_size.c: Update.
	* gnulib/import/malloca.c: Update.
	* gnulib/import/malloca.h: Update.
	* gnulib/import/malloca.valgrind: Update.
	* gnulib/import/math.in.h: Update.
	* gnulib/import/mbrtowc.c: Update.
	* gnulib/import/mbsinit.c: Update.
	* gnulib/import/mbsrtowcs-impl.h: Update.
	* gnulib/import/mbsrtowcs-state.c: Update.
	* gnulib/import/mbsrtowcs.c: Update.
	* gnulib/import/memchr.c: Update.
	* gnulib/import/memmem.c: Update.
	* gnulib/import/mempcpy.c: Update.
	* gnulib/import/memrchr.c: Update.
	* gnulib/import/mkdir.c: Update.
	* gnulib/import/mkstemp.c: Update.
	* gnulib/import/msvc-inval.c: Update.
	* gnulib/import/msvc-inval.h: Update.
	* gnulib/import/msvc-nothrow.c: Update.
	* gnulib/import/msvc-nothrow.h: Update.
	* gnulib/import/open.c: Update.
	* gnulib/import/openat-die.c: Update.
	* gnulib/import/openat-priv.h: Update.
	* gnulib/import/openat-proc.c: Update.
	* gnulib/import/openat.c: Update.
	* gnulib/import/openat.h: Update.
	* gnulib/import/opendir.c: Update.
	* gnulib/import/pathmax.h: Update.
	* gnulib/import/pipe-safer.c: Update.
	* gnulib/import/rawmemchr.c: Update.
	* gnulib/import/readdir.c: Update.
	* gnulib/import/readlink.c: Update.
	* gnulib/import/realloc.c: Update.
	* gnulib/import/ref-add.sin: Update.
	* gnulib/import/ref-del.sin: Update.
	* gnulib/import/rename.c: Update.
	* gnulib/import/rewinddir.c: Update.
	* gnulib/import/rmdir.c: Update.
	* gnulib/import/same-inode.h: Update.
	* gnulib/import/save-cwd.c: Update.
	* gnulib/import/save-cwd.h: Update.
	* gnulib/import/scratch_buffer.h: Update.
	* gnulib/import/secure_getenv.c: Update.
	* gnulib/import/setenv.c: Update.
	* gnulib/import/signal.in.h: Update.
	* gnulib/import/stat-time.c: Update.
	* gnulib/import/stat-time.h: Update.
	* gnulib/import/stat-w32.c: Update.
	* gnulib/import/stat-w32.h: Update.
	* gnulib/import/stat.c: Update.
	* gnulib/import/stdbool.in.h: Update.
	* gnulib/import/stddef.in.h: Update.
	* gnulib/import/stdint.in.h: Update.
	* gnulib/import/stdio.in.h: Update.
	* gnulib/import/stdlib.in.h: Update.
	* gnulib/import/str-two-way.h: Update.
	* gnulib/import/strchrnul.c: Update.
	* gnulib/import/strdup.c: Update.
	* gnulib/import/streq.h: Update.
	* gnulib/import/strerror-override.c: Update.
	* gnulib/import/strerror-override.h: Update.
	* gnulib/import/strerror.c: Update.
	* gnulib/import/string.in.h: Update.
	* gnulib/import/stripslash.c: Update.
	* gnulib/import/strnlen1.c: Update.
	* gnulib/import/strnlen1.h: Update.
	* gnulib/import/strstr.c: Update.
	* gnulib/import/strtok_r.c: Update.
	* gnulib/import/sys_stat.in.h: Update.
	* gnulib/import/sys_time.in.h: Update.
	* gnulib/import/sys_types.in.h: Update.
	* gnulib/import/tempname.c: Update.
	* gnulib/import/tempname.h: Update.
	* gnulib/import/time.in.h: Update.
	* gnulib/import/unistd--.h: Update.
	* gnulib/import/unistd-safer.h: Update.
	* gnulib/import/unistd.in.h: Update.
	* gnulib/import/unsetenv.c: Update.
	* gnulib/import/verify.h: Update.
	* gnulib/import/extra/snippet/warn-on-use.h: Update.
	* gnulib/import/wchar.in.h: Update.
	* gnulib/import/wctype.in.h: Update.
	* gnulib/import/xalloc-oversized.h: Update.
	* gnulib/update-gnulib.sh (GNULIB_COMMIT_SHA1): Set to
	"53e2c179f26a890fa6685af4b6c1397ee370433b".