add tbaa metadata to vtable pointer loads/stores

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153447 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenTBAA.cpp b/lib/CodeGen/CodeGenTBAA.cpp
index 148081e..9ee3f1d 100644
--- a/lib/CodeGen/CodeGenTBAA.cpp
+++ b/lib/CodeGen/CodeGenTBAA.cpp
@@ -179,3 +179,7 @@
   // For now, handle any other kind of type conservatively.
   return MetadataCache[Ty] = getChar();
 }
+
+llvm::MDNode *CodeGenTBAA::getTBAAInfoForVTablePtr() {
+  return getTBAAInfoForNamedType("vtable pointer", getRoot());
+}