gnulib: update

* lib/yyerror.c: Include config.h since the following stdio.h might be
from gnulib.

lib/.gitignore

@@ -272,3 +272,9 @@
 /binary-io.c
 /mbuiter.c
 /xsize.c
+/bitrotate.c
+/math.c
+/sig-handler.c
+/stdio.c
+/unistd.c
+/wctype-h.c

lib/yyerror.c

@@ -17,6 +17,8 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
+#include <config.h>
+
 #include <stdio.h>
 
 int yyerror (char const *);