Fix rules for parallel make.

Index: modules/wildcard/Makefile.in
--- modules/wildcard/Makefile.in.orig
+++ modules/wildcard/Makefile.in
@@ -34,7 +34,7 @@ wildcard.o : wildcard.c config.h gllib
 am--refresh :
 
 # wildcard relies on src/gllib, so we must also include files in the build dir
-gllib libgnu_wc.a : force
+gllib libgnu_wc.a &: force
 	rm -f libgnu_wc.a
 	mkdir -p gllib
 	test -f gllib/Makefile || sh config.status gllib/Makefile depfiles