Implement JsMethodMirror.constructorName.

dart/tests/lib/mirrors/stringify.dart

 // Copyright (c) 2013, 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.
 
 /// Helper methods for converting a [Mirror] to a [String].
 library test.stringify;
 
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
@@ skipping 85 matching lines @@
   if (value is ParameterMirror) return stringifyParameter(value);
   if (value is VariableMirror) return stringifyVariable(value);
   if (value is MethodMirror) return stringifyMethod(value);
   if (value is Symbol) return stringifySymbol(value);
   if (value is TypeMirror) return stringifyType(value);
   if (value == null) return '<null>';
   throw 'Unexpected value: $value';
 }
 
 expect(expected, actual) => Expect.stringEquals(expected, stringify(actual));
+
+compareSymbols(Symbol a, Symbol b) {
+  return MirrorSystem.getName(a).compareTo(MirrorSystem.getName(b));
+}