Make sure to initialize ExternalProtocolPtrTy

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148358 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index 45fe53d..159e927 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -4233,7 +4233,8 @@
 /* *** */
 
 ObjCCommonTypesHelper::ObjCCommonTypesHelper(CodeGen::CodeGenModule &cgm)
-  : VMContext(cgm.getLLVMContext()), CGM(cgm) {
+  : VMContext(cgm.getLLVMContext()), CGM(cgm), ExternalProtocolPtrTy(0) 
+{
   CodeGen::CodeGenTypes &Types = CGM.getTypes();
   ASTContext &Ctx = CGM.getContext();