Add more support for GLOBAL_CONLYFLAGS.

This will be necessary to support -std=gnu99 mode for clang 3.6, which
defaults to C11 mode (unlike prior releases that use C99).

Change-Id: Iea84582f9f12ba76b988463cbc0a20bd61042538
diff --git a/core/definitions.mk b/core/definitions.mk
index 506467f..935050d 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1013,6 +1013,7 @@
 	-c \
 	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
 	    $(PRIVATE_TARGET_GLOBAL_CFLAGS) \
+	    $(PRIVATE_TARGET_GLOBAL_CONLYFLAGS) \
 	    $(PRIVATE_ARM_CFLAGS) \
 	 ) \
 	 $(1) \
@@ -1111,6 +1112,7 @@
 	-c \
 	$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),, \
 	    $(PRIVATE_HOST_GLOBAL_CFLAGS) \
+	    $(PRIVATE_HOST_GLOBAL_CONLYFLAGS) \
 	 ) \
 	$(1) \
 	-MD -MF $(patsubst %.o,%.d,$@) -o $@ $<