Implement JsMethodMirror.constructorName.

dart/tests/lib/mirrors/constructors_test.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.
 
 library test.constructors_test;
 
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
 
@@ skipping 34 matching lines @@
          ' Biz.named: Method(s(Biz.named) in s(Biz), constructor)}',
          bizConstructors);
   print(bizConstructors);
 
   expect('[]', fooConstructors.values.single.parameters);
   expect('[]', barConstructors.values.single.parameters);
   expect('[]', bazConstructors.values.single.parameters);
   for (var constructor in bizConstructors.values) {
     expect('[]', constructor.parameters);
   }
+
+  expect('[s()]',
+         fooConstructors.values.map((m) => m.constructorName).toList());
+  expect('[s()]',
+         barConstructors.values.map((m) => m.constructorName).toList());
+  expect('[s(named)]',
+         bazConstructors.values.map((m) => m.constructorName).toList());
+  expect('[s(), s(named)]',
+         bizConstructors.values.map((m) => m.constructorName).toList()
+             ..sort(compareSymbols));
 }