[dart:io] Adds Platform.operatingSystemVersion

runtime/bin/platform_patch.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.
 
 @patch
 class _Platform {
   @patch
   static int _numberOfProcessors() native "Platform_NumberOfProcessors";
   @patch
   static String _pathSeparator() native "Platform_PathSeparator";
   @patch
   static String _operatingSystem() native "Platform_OperatingSystem";
   @patch
+  static _operatingSystemVersion() native "Platform_OperatingSystemVersion";
+  @patch
   static _localHostname() native "Platform_LocalHostname";
   @patch
   static _executable() native "Platform_ExecutableName";
   @patch
   static _resolvedExecutable() native "Platform_ResolvedExecutableName";
   @patch
   static _environment() native "Platform_Environment";
   @patch
   static List<String> _executableArguments()
       native "Platform_ExecutableArguments";
@@ skipping 20 matching lines @@
           path.startsWith('dart:') ||
           path.startsWith('data:') ||
           path.startsWith('file:')) {
         return Uri.parse(path);
       } else {
         return Uri.base.resolveUri(new Uri.file(path));
       }
     });
   }
 }