Add triple to tbaa-struct.cpp to appease bots

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180065 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/tbaa-struct.cpp b/test/CodeGen/tbaa-struct.cpp
index 3a93d75..6d593a3 100644
--- a/test/CodeGen/tbaa-struct.cpp
+++ b/test/CodeGen/tbaa-struct.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -emit-llvm -o - -O1 %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin -emit-llvm -o - -O1 %s | FileCheck %s
 //
 // Check that we generate !tbaa.struct metadata for struct copies.
 struct A {