Implement CHA through type mask and TypedSelector in the simple type inferrer.

tests/utils/dummy_compiler_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.
 
 // Smoke test of the dart2js compiler API.
 library dummy_compiler;
 
 import 'dart:async';
 import 'dart:uri';
 
@@ skipping 41 matching lines @@
                     var toString;
                   }
                   class JSFunction {}
                   class JSInt {}
                   class JSDouble {}
                   class JSNumber {}
                   class JSNull {}
                   class JSBool {}
                   var getInterceptor;""";
     } else if (uri.path.endsWith('js_helper.dart')) {
-      source = 'library jshelper; class JSInvocationMirror {}';
+      source = 'library jshelper; class JSInvocationMirror {} '
+               'class ConstantMap {} class TypeImpl {}';
     } else if (uri.path.endsWith('isolate_helper.dart')) {
       source = 'library isolatehelper; class _WorkerStub {}';
     } else {
       source = "library lib;";
     }
   } else {
    throw "unexpected URI $uri";
   }
   completer.complete(source);
   return completer.future;
@@ skipping 14 matching lines @@
               new Uri.fromComponents(scheme: 'package', path: '/'),
               provider, handler);
   result.then((String code) {
     if (code == null) {
       throw 'Compilation failed';
     }
   }, onError: (AsyncError e) {
       throw 'Compilation failed';
   });
 }