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/build/Android.executable.mk b/build/Android.executable.mk
index dfea6e1..7b03682 100644
--- a/build/Android.executable.mk
+++ b/build/Android.executable.mk
@@ -70,13 +70,14 @@
   endif
 
   ifeq ($$(art_target_or_host),target)
-  	$(call set-target-local-clang-vars)
-  	$(call set-target-local-cflags-vars,$(6))
+    $(call set-target-local-clang-vars)
+    $(call set-target-local-cflags-vars,$(6))
     LOCAL_SHARED_LIBRARIES += libdl
   else # host
     LOCAL_CLANG := $(ART_HOST_CLANG)
     LOCAL_LDLIBS := $(ART_HOST_LDLIBS)
     LOCAL_CFLAGS += $(ART_HOST_CFLAGS)
+    LOCAL_ASFLAGS += $(ART_HOST_ASFLAGS)
     ifeq ($$(art_ndebug_or_debug),debug)
       LOCAL_CFLAGS += $(ART_HOST_DEBUG_CFLAGS)
     else