Make sure that we have a real on-the-stack alloca()

Because of how Guile saves and restores continuations (by copying the
stack), and how it uses alloca to create space for debug information
on the stack, we must have an alloca() that really does use the stack,
and not one that uses the heap.

To do this, we use the Gnulib "alloca-opt" module instead of "alloca".

This commit also updates the Gnulib sources from the current Gnulib
Git repository.

m4/gnulib-comp.m4

@@ -1,5 +1,5 @@
 # DO NOT EDIT! GENERATED AUTOMATICALLY!
-# Copyright (C) 2002-2008 Free Software Foundation, Inc.
+# Copyright (C) 2002-2009 Free Software Foundation, Inc.
 #
 # This file is free software, distributed under the terms of the GNU
 # General Public License.  As a special exception to the GNU General
@@ -42,13 +42,18 @@ AC_DEFUN([gl_INIT],
   m4_pushdef([gl_LIBSOURCES_DIR], [])
   gl_COMMON
   gl_source_base='lib'
-changequote(,)dnl
-LTALLOCA=`echo "$ALLOCA" | sed 's/\.[^.]* /.lo /g;s/\.[^.]*$/.lo/'`
-changequote([, ])dnl
-AC_SUBST([LTALLOCA])
   gl_FUNC_ALLOCA
   gl_COUNT_ONE_BITS
   gl_INLINE
+  gl_LOCALCHARSET
+  LOCALCHARSET_TESTS_ENVIRONMENT="CHARSETALIASDIR=\"\$(top_builddir)/$gl_source_base\""
+  AC_SUBST([LOCALCHARSET_TESTS_ENVIRONMENT])
+  gl_FUNC_MBRLEN
+  gl_WCHAR_MODULE_INDICATOR([mbrlen])
+  gl_FUNC_MBRTOWC
+  gl_WCHAR_MODULE_INDICATOR([mbrtowc])
+  gl_FUNC_MBSINIT
+  gl_WCHAR_MODULE_INDICATOR([mbsinit])
   gl_SAFE_READ
   gl_SAFE_WRITE
   gt_TYPE_SSIZE_T
@@ -191,19 +196,27 @@ AC_DEFUN([gltests_LIBSOURCES], [
 # gnulib-tool and may be removed by future gnulib-tool invocations.
 AC_DEFUN([gl_FILE_LIST], [
   build-aux/link-warning.h
-  lib/alloca.c
   lib/alloca.in.h
+  lib/config.charset
   lib/count-one-bits.h
   lib/full-read.c
   lib/full-read.h
   lib/full-write.c
   lib/full-write.h
+  lib/localcharset.c
+  lib/localcharset.h
+  lib/mbrlen.c
+  lib/mbrtowc.c
+  lib/mbsinit.c
+  lib/ref-add.sin
+  lib/ref-del.sin
   lib/safe-read.c
   lib/safe-read.h
   lib/safe-write.c
   lib/safe-write.h
   lib/stdbool.in.h
   lib/strcasecmp.c
+  lib/streq.h
   lib/strftime.c
   lib/strftime.h
   lib/strings.in.h
@@ -216,11 +229,20 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/write.c
   m4/alloca.m4
   m4/autobuild.m4
+  m4/codeset.m4
   m4/count-one-bits.m4
   m4/extensions.m4
+  m4/glibc21.m4
   m4/gnulib-common.m4
   m4/include_next.m4
   m4/inline.m4
+  m4/localcharset.m4
+  m4/locale-fr.m4
+  m4/locale-ja.m4
+  m4/locale-zh.m4
+  m4/mbrlen.m4
+  m4/mbrtowc.m4
+  m4/mbsinit.m4
   m4/mbstate_t.m4
   m4/safe-read.m4
   m4/safe-write.m4