configure.ac: Use AC_PROG_CPP_WERROR.

	* configure.ac: Use AC_PROG_CPP_WERROR.
	* configure: Regenerate.

From-SVN: r75411

gcc/ChangeLog

+2004-01-04  Nathanael Nerode  <neroden@gcc.gnu.org>
+
+	* configure.ac: Use AC_PROG_CPP_WERROR.
+	* configure: Regenerate.
+
 2004-01-04  Zack Weinberg  <zack@codesourcery.com>
 
 	* .cvsignore: Add autom4te.cache.

gcc/configure.ac

-# configure.in for GCC
+# configure.ac for GCC
 # Process this file with autoconf to generate a configuration script.
 
-# Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2003
+# Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
 # Free Software Foundation, Inc.
 
 #This file is part of GCC.
@@ -685,6 +685,10 @@ if test $gcc_cv_glibc = yes; then
   AC_DEFINE(_GNU_SOURCE, 1, [Always define this when using the GNU C Library])
 fi
 
+# Need to reject headers which give warnings, so that the -Werror bootstrap
+# works later. *sigh*  This needs to come before all header checks.
+AC_PROG_CPP_WERROR
+
 AC_HEADER_STDC
 AC_HEADER_TIME
 gcc_AC_HEADER_STDBOOL