invariant.group-for-vptrs test fix

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@247733 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGenCXX/invariant.group-for-vptrs.cpp

-// RUN: %clang_cc1 -triple %itanium_abi_triple -emit-llvm %s -fstrict-vtable-pointers -O1 -o - -disable-llvm-optzns | FileCheck %s
+// RUN: %clang_cc1 -triple=x86_64-pc-linux-gnu -emit-llvm %s -fstrict-vtable-pointers -O1 -o - -disable-llvm-optzns | FileCheck %s
 
 struct A {
   virtual void foo();