Migrate block 163 to Dart 2.0.

tests/language_2/value_range3_test.dart

 // Copyright (c) 2013, 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 file.
 
 import 'package:expect/expect.dart';
 
 class A {
   copy(array, index1, index2) {
     if (index1 < index2 + index2) {
       // dart2js used to remove the bounds check.
       return array[index1];
     }
   }
 }
 
 main() {
   Expect.throws(() => new A().copy(new List(0), 0, 1), (e) => e is RangeError);
 }