Switch to using HOST Clang/LLVM prebuilts.

Bug: 10653601
Change-Id: Icc6c0fa224643c2e1ea0c04994b0586867a24e46
diff --git a/tools/Android.mk b/tools/Android.mk
index 691b594..51e9942 100644
--- a/tools/Android.mk
+++ b/tools/Android.mk
@@ -231,6 +231,12 @@
 
 ##################################
 
+endif # TARGET_BUILD_APPS only
+
+# Only build Clang/LLVM components when forced to.
+ifneq (true,$(FORCE_BUILD_LLVM_COMPONENTS))
+
+##################################
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libLLVM
@@ -254,6 +260,4 @@
 
 include $(BUILD_PREBUILT)
 
-##################################
-
-endif # TARGET_BUILD_APPS only
+endif #!FORCE_BUILD_LLVM_COMPONENTS