Remove uses of dart:io Options in dart2js and dartdoc.

runtime/bin/builtin.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.
 
 library builtin;
 import 'dart:io';
 
 // Corelib 'print' implementation.
 void _print(arg) {
   _Logger._printString(arg.toString());
@@ skipping 218 matching lines @@
       // Only handling file and package URIs in standalone binary.
       _logResolution('# Unknown scheme (${uri.scheme}) in $uri.');
       throw 'Not a known scheme: $uri';
   }
 
   if (_isWindows && path.startsWith('/')) {
     // For Windows we need to massage the paths a bit according to
     // http://blogs.msdn.com/b/ie/archive/2006/12/06/file-uris-in-windows.aspx
     //
     // Drop the leading / before the drive letter.
+    // TODO(14577): Handle paths like \\server\share\dir\file.
     path = path.substring(1);
     _logResolution('# Path: Removed leading / -> $path');
   }
 
   return path;
 }
 
 
 String _filePathFromFileUri(Uri uri) {
   if (!uri.host.isEmpty) {
@@ skipping 54 matching lines @@
   }
   _logResolution('# Package: $uri -> $path');
   return path;
 }
 
 
 String _filePathFromHttpUri(Uri uri) {
   _logResolution('# Path: $uri -> $uri');
   return uri.toString();
 }