Enable runtime_libart on darwin.

Change-Id: I0499bb387af827379fa4bb5e71a9770a89093c53
diff --git a/target/product/core_minimal.mk b/target/product/core_minimal.mk
index a6f9f41..313aee2 100644
--- a/target/product/core_minimal.mk
+++ b/target/product/core_minimal.mk
@@ -59,9 +59,7 @@
 
 PRODUCT_RUNTIMES := runtime_libdvm_default
 ifneq (,$(filter userdebug eng, $(TARGET_BUILD_VARIANT)))
-    ifneq ($(HOST_OS),darwin)
-        PRODUCT_RUNTIMES += runtime_libart
-    endif
+    PRODUCT_RUNTIMES += runtime_libart
 endif
 
 $(call inherit-product, $(SRC_TARGET_DIR)/product/base.mk)