Attempt to fix rtti-layout.cpp on Linux.

llvm-svn: 91581
diff --git a/clang/test/CodeGenCXX/rtti-layout.cpp b/clang/test/CodeGenCXX/rtti-layout.cpp
index fb12f3a..609ddeb 100644
--- a/clang/test/CodeGenCXX/rtti-layout.cpp
+++ b/clang/test/CodeGenCXX/rtti-layout.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -triple=x86_64-apple-darwin10 -emit-llvm -O3 -o - | FileCheck %s
+// RUN: %clang_cc1 %s -I%S -triple=x86_64-apple-darwin10 -emit-llvm -O3 -o - | FileCheck %s
 #include <typeinfo>
 
 class __pbase_type_info : public std::type_info {