Add LLVM_AS to tools.

Change-Id: If9b4900e743b9efbf4b12eee4ed5e713ce82db9b
diff --git a/core/llvm_config.mk b/core/llvm_config.mk
index 966924e..bc90b95 100644
--- a/core/llvm_config.mk
+++ b/core/llvm_config.mk
@@ -1,5 +1,6 @@
 CLANG := $(HOST_OUT_EXECUTABLES)/clang$(HOST_EXECUTABLE_SUFFIX)
 CLANG_CXX := $(HOST_OUT_EXECUTABLES)/clang++$(HOST_EXECUTABLE_SUFFIX)
+LLVM_AS := $(HOST_OUT_EXECUTABLES)/llvm-as$(HOST_EXECUTABLE_SUFFIX)
 LLVM_LINK := $(HOST_OUT_EXECUTABLES)/llvm-link$(HOST_EXECUTABLE_SUFFIX)
 
 define do-clang-flags-subst