update Makefile.extr

Makefile.extr

@@ -96,7 +96,7 @@ LIBS_BYTE=$(patsubst %.cmxa,%.cma,$(patsubst %.cmx,%.cmo,$(LIBS)))
 
 EXECUTABLES=ccomp ccomp.byte cchecklink cchecklink.byte clightgen clightgen.byte
 GENERATED=$(PARSERS:.mly=.mli) $(PARSERS:.mly=.ml) $(LEXERS:.mll=.ml) cparser/pre_parser_messages.ml \
-          $(BPARSER:.mly=.mli) $(BPARSER:.mly=.ml)
+          bfrontend/$(BPARSER:.mly=.mli) bfrontend/$(BPARSER:.mly=.ml)
 
 # Beginning of part that assumes .depend.extr already exists