Change error handling.

dart_vm_standalone/_internal_patch.dart

 // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE.md file.
 
 library dart._internal_patch;
 
 import 'dart:_patch' show
     patch;
 
 part '../third_party/dart-sdk/runtime/lib/internal_patch.dart';
 part '../third_party/dart-sdk/runtime/lib/print_patch.dart';
 part '../third_party/dart-sdk/runtime/lib/symbol_patch.dart';
 part '_internal/class_id.dart';
-
-_dynamicError(int errorKind) {
-  switch (errorKind) {
-    case 0:
-      return (String message) => new TypeError();
-
-    default:
-      throw "Unknown error";
-  }
-}