Stop using the Hashable interface.

tests/language/map_literal_test.dart

 // Copyright (c) 2011, 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.
 
 // Tests map literals.
 
 class MapLiteralTest {
   MapLiteralTest() {}
 
   static testMain() {
@@ skipping 19 matching lines @@
     var map2 = {"1":1, "2":2};
 
     Expect.equals(1, map1["a"]);
     Expect.equals(2, map1["b"]);
 
     Expect.equals(1, map2["1"]);
     Expect.equals(2, map2["2"]);
   }
 }
 
-class StaticInit  {
+class StaticInit {
   StaticInit() {}
 
   // Test construction of static const map literals
   static const map1 = const {"a":1, "b":2};
   // Test construction of static const map literals, with numbers
   static const map2 = const {"1":1, "2":2};
 
   test() {
     Expect.equals(1, map1["a"]);
     Expect.equals(2, map1["b"]);
@@ skipping 16 matching lines @@
     Expect.equals(2, map1["b"]);
 
     Expect.equals(1, map2["1"]);
     Expect.equals(2, map2["2"]);
   }
 }
 
 main() {
   MapLiteralTest.testMain();
 }