Hacky work-around for highly parallel builds.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57125

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index aad927c..182f666 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -3908,21 +3908,21 @@ build/gengtype-lex.o: $(BCONFIG_H)
 
 gengtype-parse.o build/gengtype-parse.o : gengtype-parse.c gengtype.h \
   $(SYSTEM_H)
-gengtype-parse.o: $(CONFIG_H)
+gengtype-parse.o: $(CONFIG_H) $(BCONFIG_H)
 CFLAGS-gengtype-parse.o += -DGENERATOR_FILE
 build/gengtype-parse.o: $(BCONFIG_H)
 
 gengtype-state.o build/gengtype-state.o: gengtype-state.c $(SYSTEM_H) \
   gengtype.h errors.h double-int.h version.h $(HASHTAB_H) $(OBSTACK_H) \
   $(XREGEX_H)
-gengtype-state.o: $(CONFIG_H)
+gengtype-state.o: $(CONFIG_H) $(BCONFIG_H)
 CFLAGS-gengtype-state.o += -DGENERATOR_FILE
 build/gengtype-state.o: $(BCONFIG_H)
 
 gengtype.o build/gengtype.o : gengtype.c $(SYSTEM_H) gengtype.h 	\
   rtl.def insn-notes.def errors.h double-int.h version.h $(HASHTAB_H) \
   $(OBSTACK_H) $(XREGEX_H)
-gengtype.o: $(CONFIG_H)
+gengtype.o: $(CONFIG_H) $(BCONFIG_H)
 CFLAGS-gengtype.o += -DGENERATOR_FILE
 build/gengtype.o: $(BCONFIG_H)