BREAKING CHANGE: Remove === and !== in the VM compiler

tests/language/compile_time_constant_d_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";
 
 class A {
   final x;
   final y;
   final z;
@@ skipping 10 matching lines @@
 const a2 = const A.named(99, 100);
 const a3 = const A.named2(1, 2, 3, 4);
 
 main() {
   Expect.equals(3, a1.x);
   Expect.equals(499, a1.y);
   Expect.equals(99, a1.z);
   Expect.equals(100, a1.t);
   Expect.equals("A 3 499 99 100", a1.toString());
 
-  Expect.isTrue(a1 === a2);
+  Expect.isTrue(identical(a1, a2));
 
   Expect.equals(1, a3.x);
   Expect.equals(2, a3.y);
   Expect.equals(3, a3.z);
   Expect.equals(4, a3.t);
   Expect.equals("A 1 2 3 4", a3.toString());
 }