bootstrap: sync with upstream.

* build-aux/gl/build-aux/bootstrap.in,
build-aux/gl/build-aux/extract-trace,
build-aux/gl/build-aux/funclib.sh,
build-aux/gl/build-aux/inline-source,
build-aux/gl/build-aux/options-parser: Sync with upstream.
* bootstrap: Regenerate.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: autogenerate THANKS.

More automation == less time wasted on menial tasks.
* build-aux/thanks-gen: script inspired by coreutils.
* Makefile.am (THANKS): Based on rule from coreutils/Makefile.am.
* NO-THANKS: New file. Configure thanks-gen output.
* THANKS: Remove.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: loadable modules do not require undefined symbol support.

For compatibility with OS/2 and cygwin, modules must be compiled
with no undefined symbols.
* Makefile.am (AM_LDFLAGS): Add -no-undefined flag.
Reported by Ko Myung-Hun

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: loadable modules files do not require version numbers.

Modules are loaded by libltdl.  Arguably, loading from the .la
pseudo-library should work irrespective of platform library object
file-naming schemes; but in reality, M4 loads modules by basename
anyway, so we shouldn't put a platform specific version number in
the module filename anyway.
* Makefile.am (module_ldflags): Add -avoid-version flag.
Reported by KO Myung-Hun

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: append $EXEEXT suffix to /bin/sh.

Without $EXEEXT, /bin/sh cannot be located on OS/2.
* build-aux/m4/m4-syscmd.m4 (M4_SYSCMD): append $EXEEXT suffix
to /bin/sh.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: add -Zargs-resp to LDFLAGS on OS/2.

-Zargs-resp enables a response file support on OS/2.
* configure.ac (OS2_LDFLAGS): Add -Zargs-resp on *-*-os2*.
* Makefile.am (AM_LDFLAGS): Add OS2_LDFLAGS.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
m4: fdopen() with a text mode explicitly on OS/2.

On OS/2 kLIBC, fdopen() creates a stream in a mode of a file
descriptor. So specify "t" to open a stream in a text mode explicitly
on OS/2.
* modules/gnu.c (m4_esyscmd): fdopen() in a text mode on OS/2.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
modules: support .dll suffix.

* m4/module.c (m4__module_open): Support .dll suffix in module
names.
* m4/path.c (FILE_SUFFIXES): Likewise for include builtin.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
modules: fall-back to system dlopen search path.

* m4/module.c (m4__module_open): If the module search function
cannot find a matching module, fall-back to the system dlopen
search path.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
modules: support _ symbol prefix requirement for dlsym.

* configure.ac (LT_FUNC_DLSYM_USCORE): Call it to set NEED_USCORE.
* m4/module.c (uscore_sym): New function.  Use this to prepend an
underscore if NEED_USCORE was set at configure time.
Reported by KO Myung-Hun

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
modules: support non-posix PATH_SEPARATOR.

* configure.ac (PATH_SEPARATOR): Propagate to config.h.
* m4/path.c (search_path_env_init): Respect PATH_SEPARATOR.
Reported by KO Myung-Hun

Signed-off-by: Gary V. Vaughan <gary@gnu.org>