Remove generation of repl_gram.h

It was apparently never necessary.

src/backend/Makefile

@@ -311,7 +311,6 @@ maintainer-clean: distclean
 	      catalog/postgres.description \
 	      catalog/postgres.shdescription \
 	      replication/repl_gram.c \
-	      replication/repl_gram.h \
 	      replication/repl_scanner.c \
 	      utils/fmgroids.h \
 	      utils/fmgrtab.c \

src/backend/replication/.gitignore

 /repl_gram.c
-/repl_gram.h
 /repl_scanner.c

src/backend/replication/Makefile

@@ -22,11 +22,9 @@ include $(top_srcdir)/src/backend/common.mk
 # repl_scanner is compiled as part of repl_gram
 repl_gram.o: repl_scanner.c
 
-# See notes in src/backend/parser/Makefile about the following two rules
-
 repl_gram.c: repl_gram.y
 ifdef BISON
-	$(BISON) -d $(BISONFLAGS) -o $@ $<
+	$(BISON) $(BISONFLAGS) -o $@ $<
 else
 	@$(missing) bison $< $@
 endif