make: Make .o files depend on Makefile, at least for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94184 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Makefile.rules b/Makefile.rules
index 5987e48..3d436c4 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -1353,17 +1353,17 @@
 DEPEND_MOVEFILE = then $(MV) -f "$(ObjDir)/$*.d.tmp" "$(ObjDir)/$*.d"; \
                   else $(RM) "$(ObjDir)/$*.d.tmp"; exit 1; fi
 
-$(ObjDir)/%.o: %.cpp $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.cpp $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_SRC_DIR)/Makefile
 	$(Echo) "Compiling $*.cpp for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.CXX) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
 
-$(ObjDir)/%.o: %.cc $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.cc $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_SRC_DIR)/Makefile
 	$(Echo) "Compiling $*.cc for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.CXX) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)
 
-$(ObjDir)/%.o: %.c $(ObjDir)/.dir $(BUILT_SOURCES)
+$(ObjDir)/%.o: %.c $(ObjDir)/.dir $(BUILT_SOURCES) $(PROJ_SRC_DIR)/Makefile
 	$(Echo) "Compiling $*.c for $(BuildMode) build" $(PIC_FLAG)
 	$(Verb) if $(Compile.C) $(DEPEND_OPTIONS) $< -o $(ObjDir)/$*.o ; \
 	        $(DEPEND_MOVEFILE)