* configure.in: Port alloca to AIX 3.

ChangeLog

@@ -4,7 +4,8 @@
 	* .bzrignore: Add lib/alloca.h.
 	* Makefile.in (GNULIB_MODULES): Add alloca-opt.
 	* configure.in (AC_FUNC_ALLOCA): Remove almost all the alloca stuff,
-	as gnulib now does that for us.  Put alloca check after gl_INIT.
+	as gnulib now does that for us.  Put alloca check in config.h.
+	Include <alloca.h> before any other include file, for AIX 3.
 	* lib/gnulib.mk, m4/gl-comp.m4: Regenerate.
 	* lib/alloca.in.h, m4/alloca.m4: New files, from gnulib.
 

configure.in

@@ -2678,14 +2678,6 @@ gl_ASSERT_NO_GNULIB_POSIXCHECK
 gl_ASSERT_NO_GNULIB_TESTS
 gl_INIT
 
-# Check for alloca.
-dnl src/alloca.c has been removed.  Could also check if $ALLOCA is set?
-dnl FIXME is there an autoconf test that does the right thing, without
-dnl needing to call A_M_E afterwards?
-if test x"$ac_cv_func_alloca_works" != xyes; then
-   AC_MSG_ERROR( [a system implementation of alloca is required] )
-fi
-
 # UNIX98 PTYs.
 AC_CHECK_FUNCS(grantpt)
 
@@ -3458,6 +3450,12 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 ])dnl
 
 AH_BOTTOM([
+/* On AIX 3 this must be included before any other include file.  */
+#include <alloca.h>
+#if ! HAVE_ALLOCA
+# error "alloca not available on this machine"
+#endif
+
 /* Define AMPERSAND_FULL_NAME if you use the convention
    that & in the full name stands for the login id.  */
 /* Turned on June 1996 supposing nobody will mind it.  */
@@ -3533,7 +3531,6 @@ AH_BOTTOM([
 
 #include <string.h>
 #include <stdlib.h>
-#include <alloca.h>
 
 #ifndef HAVE_STRCHR
 #define strchr(a, b) index (a, b)