Move Options to dart:io.

tests/compiler/dart2js/deferred_load_graph_segmentation_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.
 
 // Test of the graph segmentation algorithm used by deferred loading
 // to determine which elements can be deferred and which libraries
 // much be included in the initial download (loaded eagerly).
 
 import 'dart:async' show Future;
 import 'dart:uri' show Uri;
+import 'dart:io';
 
 import '../../../sdk/lib/_internal/compiler/implementation/apiimpl.dart'
        show Compiler;
 
 import '../../../sdk/lib/_internal/compiler/implementation/dart2jslib.dart'
        as dart2js;
 
 import '../../../sdk/lib/_internal/compiler/implementation/filenames.dart'
        show getCurrentDirectory;
 
@@ skipping 75 matching lines @@
 class MyClass {
   const MyClass();
 
   foo(x) {
     new Expando();
     return (x - 3) ~/ 2;
   }
 }
 """,
 };