Make test standalone/src/io/ManyEchoServerTest compile

tests/standalone/src/io/ManyEchoServerTest.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.
 // Stress test isolate generation.
 
-#library("ManyEchoServerTest.dart");
 #import("EchoServerTest.dart", prefix: "single");
 
 class ManyEchoServerTest {
   static testMain() {
     for (int i = 0; i < 5000; i++) {
       single.EchoServerTest.testMain();
     }
   }
 }
 
 main() {
   ManyEchoServerTest.testMain();
 }