Fix directory-listing, directory-deletion and file deletion, when links are involved.

tests/standalone/io/file_system_links_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 "dart:io";
 import "dart:isolate";
 
 
 createLink(String dst, String link, void callback()) {
   new Link(link).create(dst).then((_) => callback());
@@ skipping 188 matching lines @@
 
 
 testDirectoryListingBrokenLink() {
   var keepAlive = new ReceivePort();
   var temp = new Directory('').createTempSync();
   var x = '${temp.path}${Platform.pathSeparator}x';
   var link = '${temp.path}${Platform.pathSeparator}link';
   var doesNotExist = 'this_thing_does_not_exist';
   new File(x).createSync();
   createLink(doesNotExist, link, () {
-    Expect.throws(() => temp.listSync(recursive: true),
-                  (e) => e is DirectoryIOException);
+    temp.listSync(recursive: true);  // No exceptions.
     var files = [];
     var dirs = [];
+    var links = [];
     var errors = [];
     temp.list(recursive: true).listen(
         (entity) {
           if (entity is File) {
             files.add(entity.path);
+          } else if (entity is Link) {
+            links.add(entity.path);
           } else {
             Expect.isTrue(entity is Directory);
             dirs.add(entity.path);
           }
         },
         onError: (e) => errors.add(e),
         onDone: () {
           Expect.equals(1, files.length);
           Expect.isTrue(files[0].endsWith(x));
+          Expect.equals(1, links.length);
+          Expect.isTrue(links[0].endsWith(link));
           Expect.equals(0, dirs.length);
-          Expect.equals(1, errors.length);
-          Expect.isTrue(errors[0].toString().contains(link));
+          Expect.equals(0, errors.length);
           temp.deleteSync(recursive: true);
           keepAlive.close();
         });
   });
 }
 
 
 main() {
   testFileExistsCreate();
   testFileDelete();
   testFileWriteRead();
   testDirectoryExistsCreate();
   testDirectoryDelete();
   testDirectoryListing();
   testDirectoryListingBrokenLink();
 }