Migrate block 163 to Dart 2.0.

tests/language_strong/value_range2_test.dart

-// Copyright (c) 2012, 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";
-
-int inscrutable(int x) => x == 0 ? 0 : x | inscrutable(x & (x - 1));
-
-foo() {
-  int x = 0;
-  if (inscrutable(0) == 0) x = -2; // x is now in range [-2 .. 0].
-  int y = 2;
-  if (inscrutable(0) == 0) y = 4; // y is now in range [2 .. 4].
-  int i = y - x; // i should be in range [2 .. 6].
-  i -= 4; // i should be in range [-2 .. 2]. Actual value: 2.
-  var a = const [1];
-  return a[i];
-}
-
-main() {
-  Expect.throws(() => foo(), (e) => e is RangeError);
-}