Update mirror tests for removed API.

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';
 
 import 'stringify.dart';
 
+constructorsOf(ClassMirror cm) {
+  var result = new Map();
+  cm.declarations.forEach((k,v) {
+    if(v is MethodMirror && v.isConstructor) result[k] = v;
+  });
+  return result;
+}
+
 class Foo {
 }
 
 class Bar {
   Bar();
 }
 
 class Baz {
   Baz.named();
 }
 
 class Biz {
   Biz();
   Biz.named();
 }
 
 main() {
   ClassMirror fooMirror = reflectClass(Foo);
-  Map<Symbol, MethodMirror> fooConstructors = fooMirror.constructors;
+  Map<Symbol, MethodMirror> fooConstructors = constructorsOf(fooMirror);
   ClassMirror barMirror = reflectClass(Bar);
-  Map<Symbol, MethodMirror> barConstructors = barMirror.constructors;
+  Map<Symbol, MethodMirror> barConstructors = constructorsOf(barMirror);
   ClassMirror bazMirror = reflectClass(Baz);
-  Map<Symbol, MethodMirror> bazConstructors = bazMirror.constructors;
+  Map<Symbol, MethodMirror> bazConstructors = constructorsOf(bazMirror);
   ClassMirror bizMirror = reflectClass(Biz);
-  Map<Symbol, MethodMirror> bizConstructors = bizMirror.constructors;
+  Map<Symbol, MethodMirror> bizConstructors = constructorsOf(bizMirror);
 
   expect('{Foo: Method(s(Foo) in s(Foo), constructor)}', fooConstructors);
   expect('{Bar: Method(s(Bar) in s(Bar), constructor)}', barConstructors);
   expect('{Baz.named: Method(s(Baz.named) in s(Baz), constructor)}',
          bazConstructors);
   expect('{Biz: Method(s(Biz) in s(Biz), constructor),'
          ' 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));
 }