bootstrap: sync with upstream.

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

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.
* configure.ac (with_syscmd_shell): append $EXEEXT suffix to /bin/sh.
* THANKS: Add KO Myung-Hun.
* NEWS: Update.

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*.
* src/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.
* src/builtin.c (m4_esyscmd): fdopen() in a text mode on OS/2.

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