Revert my last change due to problems on other platforms.

tests/language/src/MutuallyRecursiveConstConstructorNegativeTest.dart

Index: tests/language/src/MutuallyRecursiveConstConstructorNegativeTest.dart
===================================================================
--- tests/language/src/MutuallyRecursiveConstConstructorNegativeTest.dart	(revision 6128)
+++ tests/language/src/MutuallyRecursiveConstConstructorNegativeTest.dart	(working copy)
@@ -1,19 +0,0 @@
-// 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.
-
-class B {
-  final test = const A(1, b: 2);
-  const B();
-}
-
-class A {
-  final x;
-  final y;
-  const A(a, [b]) : x = a, y = b;
-  final test = const B();
-}
-
-void main() {
-  print(new A(1));
-}