Move unittest from lib to pkg.

tests/lib/mirrors/mirrors_test.dart

 // Copyright (c) 2011, 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.
 
 // TODO(rmacnak): Move the existing mirror tests here (a place for 
 // cross-implementation tests).
 
 #library("MirrorsTest.dart");
 #import("dart:mirrors");
-#import("../../../lib/unittest/unittest.dart");
+#import("../../../pkg/unittest/unittest.dart");
 
 var topLevelField;
 
 class Class {
   Class() { this.field = "default value"; }
   Class.withInitialValue(this.field);
   var field;
   static var staticField;
 }
 
@@ skipping 62 matching lines @@
 }
 
 main() {
   var mirrors = currentMirrorSystem();
 
   test("Test field access", () { testFieldAccess(mirrors); });
   test("Test closure mirrors", () { testClosureMirrors(mirrors); });
   test("Test invoke constructor", () { testInvokeConstructor(mirrors); });
 }