Enable darwin target build for art.

Change-Id: I8fc04258360d663d2fcd07c307fdfdd2981cdd19
diff --git a/build/Android.common.mk b/build/Android.common.mk
index fcaa2bd..bfb1f9b 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -25,8 +25,8 @@
 #
 ART_BUILD_TARGET_NDEBUG ?= true
 ART_BUILD_TARGET_DEBUG ?= true
-ART_BUILD_HOST_NDEBUG ?= true
-ART_BUILD_HOST_DEBUG ?= true
+ART_BUILD_HOST_NDEBUG ?= $(WITH_HOST_DALVIK)
+ART_BUILD_HOST_DEBUG ?= $(WITH_HOST_DALVIK)
 
 ifeq ($(ART_BUILD_TARGET_NDEBUG),false)
 $(info Disabling ART_BUILD_TARGET_NDEBUG)