Fix library syntax

runtime/bin/builtin.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("builtin");
-#import("dart:uri");
+library builtin;
+import 'dart:uri';
 
 // Corelib 'print' implementation.
 void _print(arg) {
   _Logger._printString(arg.toString());
 }
 
 class _Logger {
   static void _printString(String s) native "Logger_PrintString";
 }
 
@@ skipping 132 matching lines @@
   var path;
   if (_packageRoot !== null) {
     path = "${_packageRoot}${uri.path}";
   } else {
     path = _entrypoint.resolve('packages/${uri.path}').path;
   }
 
   _logResolution("# Package: $path");
   return path;
 }