Move getters from Options to Platform

tests/standalone/io/skipping_dart2js_compilations_helper.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.
 
 import 'dart:io';
 
 main() {
-  var outputFile = new Options().arguments[0];
+  var outputFile = Platform.arguments[0];
   var file = new File(outputFile);
   file.createSync();
 }