Revert "Move dart2jslib parts into separate libraries."

tests/compiler/dart2js/simple_inferrer_unregister_call_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.
 
-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 = '';
 class A {
   operator+(other) => other;
 }
 
 foo() {
   // The following '+' call will first say that it may call A::+,
   // String::+, or int::+. After all methods have been analyzed, we know
@@ skipping 18 matching lines @@
 
     checkReturnInClass(String className, String methodName, type) {
       var cls = findElement(compiler, className);
       var element = cls.lookupLocalMember(methodName);
       Expect.equals(type, typesInferrer.getReturnTypeOfElement(element));
     }
 
     checkReturnInClass('A', '+', compiler.typesTask.uint31Type);
   }));
 }