Give conversions of block pointers to ObjC pointers a different cast kind

than conversions of C pointers to ObjC pointers.  In order to ensure that
we've caught every case, add asserts to CastExpr that strictly determine
which cast kind is used for which kind of bit cast.

llvm-svn: 139352

clang/lib/CodeGen/CGExprScalar.cpp

@@ -1028,7 +1028,8 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
     return EmitLoadOfLValue(CGF.MakeAddrLValue(V, DestTy));
   }
       
-  case CK_AnyPointerToObjCPointerCast:
+  case CK_CPointerToObjCPointerCast:
+  case CK_BlockPointerToObjCPointerCast:
   case CK_AnyPointerToBlockPointerCast:
   case CK_BitCast: {
     Value *Src = Visit(const_cast<Expr*>(E));