Don't build compiler_rt if the user is just building with tapas.

Bug: 14904943

Change-Id: If45cd9115e555b80087122488e967f7fd6e8b063
diff --git a/Android.mk b/Android.mk
index bd6e060..2a0ce82 100644
--- a/Android.mk
+++ b/Android.mk
@@ -17,6 +17,8 @@
 
 LOCAL_PATH := $(call my-dir)
 
+ifeq (,$(TARGET_BUILD_APPS))
+
 # The following list contains platform-independent functionalities.
 #
 # Skip apple_versioning.c since it is unused.
@@ -379,3 +381,5 @@
 include $(BUILD_HOST_SHARED_LIBRARY)
 
 endif
+
+endif # TARGET_BUILD_APPS only