Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -4093,15 +4093,20 @@
 
   llvm::Constant *Zero = llvm::Constant::getNullValue(Int32Ty);
   llvm::Constant *Zeros[] = { Zero, Zero };
-
+  
   // If we don't already have it, get __CFConstantStringClassReference.
   if (!CFConstantStringClassRef) {
     llvm::Type *Ty = getTypes().ConvertType(getContext().IntTy);
     Ty = llvm::ArrayType::get(Ty, 0);
-    llvm::GlobalValue *GV = cast<llvm::GlobalValue>(
-        CreateRuntimeVariable(Ty, "__CFConstantStringClassReference"));
-
+    llvm::Constant *CGV =
+        CreateRuntimeVariable(Ty, "__CFConstantStringClassReference");
+    llvm::GlobalValue *GV = dyn_cast<llvm::GlobalValue>(CGV);
+    
     if (getTriple().isOSBinFormatCOFF()) {
+      // Instead of using a cast<>, just assert if it's null, this is
+      // consistent with old behavior for this target as it would fail
+      // on the cast<> instead.
+      assert(GV && "isa<CFConstantStringClassReference> isn't a GlobalValue");
       IdentifierInfo &II = getContext().Idents.get(GV->getName());
       TranslationUnitDecl *TUDecl = getContext().getTranslationUnitDecl();
       DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
@@ -4119,11 +4124,12 @@
         GV->setLinkage(llvm::GlobalValue::ExternalLinkage);
       }
     }
-    setDSOLocal(GV);
+    if (GV)
+      setDSOLocal(GV);
 
     // Decay array -> ptr
     CFConstantStringClassRef =
-        llvm::ConstantExpr::getGetElementPtr(Ty, GV, Zeros);
+        llvm::ConstantExpr::getGetElementPtr(Ty, CGV, Zeros);
   }
 
   QualType CFTy = getContext().getCFConstantStringType();