Make some warnings impossible to override.

These CFLAGS and CPPFLAGS will always be added last, and are
controlled by the build system. This way we can add warnings that
users are not allowed to disable.

Change-Id: Id71f69249078f62ca2687ecbf764aff0fd3a1c1b
diff --git a/core/definitions.mk b/core/definitions.mk
index 37f7d9d..9845556 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -990,6 +990,8 @@
 	$(PRIVATE_CFLAGS) \
 	$(PRIVATE_CPPFLAGS) \
 	$(PRIVATE_DEBUG_CFLAGS) \
+	$(GLOBAL_CFLAGS_NO_OVERRIDE) \
+	$(GLOBAL_CPPFLAGS_NO_OVERRIDE) \
 	-MD -MF $(patsubst %.o,%.d,$@) -o $@ $<
 $(transform-d-to-p)
 endef
@@ -1022,7 +1024,11 @@
 
 define transform-c-to-o-no-deps
 @echo "target $(PRIVATE_ARM_MODE) C: $(PRIVATE_MODULE) <= $<"
-$(call transform-c-or-s-to-o-no-deps, $(PRIVATE_CFLAGS) $(PRIVATE_CONLYFLAGS) $(PRIVATE_DEBUG_CFLAGS))
+$(call transform-c-or-s-to-o-no-deps, \
+    $(PRIVATE_CFLAGS) \
+    $(PRIVATE_CONLYFLAGS) \
+    $(PRIVATE_DEBUG_CFLAGS) \
+    $(GLOBAL_CFLAGS_NO_OVERRIDE))
 endef
 
 define transform-s-to-o-no-deps