Add LOCAL_CONLYFLAGS.

To pass compiler flags
LOCAL_CFLAGS: to both C and C++ files;
LOCAL_CONLYFLAGS: to only C files but not C++ files;
LOCAL_CPPFLAGS: to only C++ file.
LOCAL_CPPFLAGS and LOCAL_CONLYFLAGS can override flags in LOCAL_CFLAGS.

Bug: 6967573
Change-Id: I88d9de0980e451b94bc7ae8c741ea2030eada3e1
diff --git a/core/definitions.mk b/core/definitions.mk
index e8ec8a7..2ab366b 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -930,7 +930,7 @@
 
 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) $(PRIVATE_DEBUG_CFLAGS))
+$(call transform-c-or-s-to-o-no-deps, $(PRIVATE_CFLAGS) $(PRIVATE_CONLYFLAGS) $(PRIVATE_DEBUG_CFLAGS))
 endef
 
 define transform-s-to-o-no-deps
@@ -1017,7 +1017,7 @@
 
 define transform-host-c-to-o-no-deps
 @echo "host C: $(PRIVATE_MODULE) <= $<"
-$(call transform-host-c-or-s-to-o-no-deps, $(PRIVATE_CFLAGS) $(PRIVATE_DEBUG_CFLAGS))
+$(call transform-host-c-or-s-to-o-no-deps, $(PRIVATE_CFLAGS) $(PRIVATE_CONLYFLAGS) $(PRIVATE_DEBUG_CFLAGS))
 endef
 
 define transform-host-s-to-o-no-deps