c-parser: make table.ML depend on Makefile

Since the contents of the generated table.ML depend on the Makefile,
the Makefile itself should be a dependency.

Signed-off-by: Gerwin Klein <gerwin.klein@proofcraft.systems>

tools/c-parser/standalone-parser/Makefile

@@ -52,7 +52,7 @@ include $(STP_PFX)/../Makefile
 
 STP_CLEAN_TARGETS := $(STPARSERS) $(TOKENIZERS) $(STP_PFX)/c-parser.o $(STP_PFX)/table.ML
 
-$(STP_PFX)/table.ML: $(ISABELLE_HOME)/src/Pure/General/table.ML
+$(STP_PFX)/table.ML: $(ISABELLE_HOME)/src/Pure/General/table.ML $(STP_PFX)/Makefile
 	sed -e '/\(\* cache \*\)/,/final.declarations/d' < $< | \
 	sed -e "s/^  val unsynchronized_cache:.*a/  (* removed unsynchronized_cache *)/" > $@