Compile host libRS with clang.

bug 16513433

Change-Id: I70e79d35e34f408f31f7e69347024fdc1baefda7
diff --git a/Android.mk b/Android.mk
index 685e555..e8ec005 100644
--- a/Android.mk
+++ b/Android.mk
@@ -265,6 +265,8 @@
 
 LOCAL_STATIC_LIBRARIES := libcutils libutils liblog
 
+LOCAL_CLANG := true
+
 include $(BUILD_HOST_STATIC_LIBRARY)
 
 LLVM_ROOT_PATH := external/llvm