Move getters from Options to Platform

tests/standalone/io/process_stdin_transform_unsubscribe_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.
 //
 // Process test program to test process communication.
 //
 // VMOptions=
 // VMOptions=--short_socket_read
 // VMOptions=--short_socket_write
 // VMOptions=--short_socket_read --short_socket_write
@@ skipping 17 matching lines @@
   });
 }
 
 main() {
   var scriptName = "process_stdin_transform_unsubscribe_script.dart";
   var scriptFile = new File("tests/standalone/io/$scriptName");
   if (!scriptFile.existsSync()) {
     scriptFile = new File("../tests/standalone/io/$scriptName");
   }
   Expect.isTrue(scriptFile.existsSync());
-  test(Process.start(new Options().executable, [scriptFile.path]), 0);
+  test(Process.start(Platform.executable, [scriptFile.path]), 0);
 }