Move dart2jslib parts into separate libraries.

tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart

Index: tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart
diff --git a/tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart b/tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart
index 5c2e11fa48569e95b6ab8fc6188b79ca19338c70..06bba807adfc767ef6aef88963dade0d860e6cb8 100644
--- a/tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart
+++ b/tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart
@@ -2,10 +2,10 @@
 // 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.
 
+import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
-import "package:async_helper/async_helper.dart";
+
 import 'compiler_helper.dart';
-import 'parser_helper.dart';
 
 const String TEST = """
 var a = '';