Add missing files from previous commit

tests/standalone/io/delete_symlink_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';
+
+void main() {
+  // temp/
+  //   a/
+  //     file.txt
+  //   b/
+  //     a_link -> a
+  var d = new Directory("").createTempSync();
+  var a = new Directory("${d.path}/a");
+  a.createSync();
+
+  var b = new Directory("${d.path}/b");
+  b.createSync();
+
+  var f = new File("${d.path}/a/file.txt");
+  f.createSync();
+  Expect.isTrue(f.existsSync());
+
+  // Create a symlink (or junction on Windows) from
+  // temp/b/a_link to temp/a.
+  var cmd = "ln";
+  var args = ['-s', "${d.path}/b/a_link", "${d.path}/a"];
+
+  if (Platform.operatingSystem == "windows") {
+    cmd = "cmd";
+    args = ["/c", "mklink", "/j", "${d.path}\\b\\a_link", "${d.path}\\a"];
+  }
+
+  var keepAlive = new ReceivePort();
+
+  Process.run(cmd, args).then((_) {
+    // Delete the directory containing the junction.
+    b.deleteSync(recursive: true);
+
+    // We should not have recursed through a_link into a.
+    Expect.isTrue(f.existsSync());
+
+    // Clean up after ourselves.
+    d.deleteSync(recursive: true);
+
+    // Terminate now that we are done with everything.
+    keepAlive.close();
+  });
+}