CL2: Update paths to reflect new lib structure.

sdk/lib/_internal/compiler/implementation/dart2js.dart

 // Copyright (c) 2012, 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.
 
 #library('dart2js');
 
 #import('dart:io');
 #import('dart:uri');
 #import('dart:utf');
 
 #import('../compiler.dart', prefix: 'api');
 #import('colors.dart', prefix: 'colors');
 #import('source_file.dart');
 #import('filenames.dart');
 #import('util/uri_extras.dart');
 
-const String LIBRARY_ROOT = '../../../..';
+const String LIBRARY_ROOT = '../../../../..';
 const String OUTPUT_LANGUAGE_DART = 'Dart';
 
 typedef void HandleOption(String option);
 
 class OptionHandler {
   String pattern;
   HandleOption handle;
 
   OptionHandler(this.pattern, this.handle);
 }
@@ skipping 398 matching lines @@
     } catch (ignored) {
       print('Internal error: error while printing exception');
     }
     try {
       print(trace);
     } finally {
       exit(253); // 253 is recognized as a crash by our test scripts.
     }
   }
 }