* bin/autoupdate.in: Trace AU_DEFINE instead of AU_DEFUN.

* bin/autoupdate.in: Trace AU_DEFINE instead of AU_DEFUN.
* doc/autoconf.texi: Don't say that the third parameter
is broken.
* lib/autoconf/autoupdate.m4 (AU_DEFINE): New dummy macro.
(AU_DEFUN): Honor the third parameter, create autoupdate
macros with AU_DEFINE.
* lib/autoconf/headers.m4 (AC_USG, AC_MEMORY_H,
AC_DIR_HEADER): Use AU_DEFUN's third parameter.
* lib/autoconf/lang.m4 (AC_LANG_SAVE): Likewise.
* lib/autoconf/programs.m4 (AC_RSH): Likewise.
* lib/autoconf/specific.m4 (AC_HAVE_POUNDBANG,
AC_ARG_ARRAY, AC_CYGWIN, AC_EMXOS2, AC_MINGW32,
AC_XENIX_DIR): Likewise.
* lib/autoconf/types.m4 (AC_INT_16_BITS, AC_LONG_64_BITS,
AC_STRUCT_ST_BLKSIZE, AC_STRUCT_ST_RDEV): Likewise.
* lib/autoconf/status.m4: Remove FIXME.
* tests/local.at (AT_CHECK_AU_MACRO): Ignore stderr, check
that the macro is not present anymore in the updated
configure.ac.
* tests/tools.at (autoupdate AC_LINK_FILES): Ignore stderr
of autoupdate.