Allow enabling RTTI in a module.

Change-Id: Ie8ce920e3ccb7e53bdf917d8ac5a386df3e7836a
diff --git a/core/binary.mk b/core/binary.mk
index 53534d6..d6ccfbf 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -574,6 +574,9 @@
     $(foreach lib,$(LOCAL_STATIC_LIBRARIES) $(LOCAL_WHOLE_STATIC_LIBRARIES), \
       NOTICE-$(if $(LOCAL_IS_HOST_MODULE),HOST,TARGET)-STATIC_LIBRARIES-$(lib))
 
+# Default is -fno-rtti.
+LOCAL_RTTI_FLAG ?= -fno-rtti
+
 ###########################################################
 # Rule-specific variable definitions
 ###########################################################
@@ -581,6 +584,7 @@
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_ASFLAGS := $(LOCAL_ASFLAGS)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CFLAGS := $(LOCAL_CFLAGS)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_CPPFLAGS := $(LOCAL_CPPFLAGS)
+$(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_RTTI_FLAG := $(LOCAL_RTTI_FLAG)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_DEBUG_CFLAGS := $(debug_cflags)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_C_INCLUDES := $(LOCAL_C_INCLUDES)
 $(LOCAL_INTERMEDIATE_TARGETS): PRIVATE_LDFLAGS := $(LOCAL_LDFLAGS)
diff --git a/core/definitions.mk b/core/definitions.mk
index 8fb0215..4baf31e 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -868,7 +868,7 @@
 	    $(PRIVATE_TARGET_GLOBAL_CPPFLAGS) \
 	    $(PRIVATE_ARM_CFLAGS) \
 	 ) \
-	-fno-rtti \
+	$(PRIVATE_RTTI_FLAG) \
 	$(PRIVATE_CFLAGS) \
 	$(PRIVATE_CPPFLAGS) \
 	$(PRIVATE_DEBUG_CFLAGS) \