Mirrors overhaul.

dart/tests/compiler/dart2js_extra/mirror_type_inference_function_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.
 
 // Test that type inference sees the call to `fisk` from the mirror system
 // and not infers the argument to be an integer.
 library test;
 
 @MirrorsUsed(targets: 'fisk', override: '*')
 import 'dart:mirrors';
 
 import 'package:expect/expect.dart';
 
 bool fisk(a) => a is int;
 
 main() {
   Expect.isTrue(fisk(1));
-  var lm = currentMirrorSystem().findLibrary(const Symbol('test')).single;
+  var lm = currentMirrorSystem().findLibrary(const Symbol('test'));
   Expect.isFalse(lm.invoke(const Symbol('fisk'), ['hest']).reflectee);
 }