If heap poisoning is on, pass the relevant flag to LOCAL_ASFLAGS.

This change ensures assembly files honoring heap poisoning
(notably used by stub_test) are compiled with
-DART_HEAP_POISONING=1 when this feature is turned on.

Bug: 21621105
Change-Id: I13fe456cd2733a09bdfd3a9808cfd70513b14698
diff --git a/test/Android.libnativebridgetest.mk b/test/Android.libnativebridgetest.mk
index 5a5f725..e8cc7e4 100644
--- a/test/Android.libnativebridgetest.mk
+++ b/test/Android.libnativebridgetest.mk
@@ -60,6 +60,7 @@
   else # host
     LOCAL_CLANG := $(ART_HOST_CLANG)
     LOCAL_CFLAGS := $(ART_HOST_CFLAGS) $(ART_HOST_DEBUG_CFLAGS)
+    LOCAL_ASFLAGS := $(ART_HOST_ASFLAGS)
     LOCAL_SHARED_LIBRARIES := libcutils
     LOCAL_LDLIBS := $(ART_HOST_LDLIBS) -ldl -lpthread
     ifeq ($(HOST_OS),linux)