Use metadata annotation @patch for patch classes

runtime/lib/mirrors_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.
 
 import "dart:_internal" as internal;
 
 /**
  * Returns a [MirrorSystem] for the current isolate.
  */
-patch MirrorSystem currentMirrorSystem() {
+@patch MirrorSystem currentMirrorSystem() {
   return _Mirrors.currentMirrorSystem();
 }
 
 /**
  * Returns an [InstanceMirror] for some Dart language object.
  *
  * This only works if this mirror system is associated with the
  * current running isolate.
  */
-patch InstanceMirror reflect(Object reflectee) {
+@patch InstanceMirror reflect(Object reflectee) {
   return _Mirrors.reflect(reflectee);
 }
 
 /**
  * Returns a [ClassMirror] for the class represented by a Dart
  * Type object.
  *
  * This only works with objects local to the current isolate.
  */
-patch ClassMirror reflectClass(Type key) {
+@patch ClassMirror reflectClass(Type key) {
   return _Mirrors.reflectClass(key);
 }
 
-patch TypeMirror reflectType(Type key) {
+@patch TypeMirror reflectType(Type key) {
   return _Mirrors.reflectType(key);
 }
 
-patch class MirrorSystem {
-  /* patch */ LibraryMirror findLibrary(Symbol libraryName) {
+@patch class MirrorSystem {
+  /* @patch */ LibraryMirror findLibrary(Symbol libraryName) {
     var candidates =
         libraries.values.where((lib) => lib.simpleName == libraryName);
     if (candidates.length == 1) {
       return candidates.single;
     }
     if (candidates.length > 1) {
       var uris = candidates.map((lib) => lib.uri.toString()).toList();
       throw new Exception("There are multiple libraries named "
                           "'${getName(libraryName)}': $uris");
     }
     throw new Exception("There is no library named '${getName(libraryName)}'");
   }
 
-  /* patch */ static String getName(Symbol symbol) {
+  /* @patch */ static String getName(Symbol symbol) {
     return internal.Symbol.getUnmangledName(symbol);
   }
 
-  /* patch */ static Symbol getSymbol(String name, [LibraryMirror library]) {
+  /* @patch */ static Symbol getSymbol(String name, [LibraryMirror library]) {
     if ((library != null && library is! _LocalLibraryMirror) ||
         ((name.length > 0) && (name[0] == '_') && (library == null))) {
       throw new ArgumentError(library);
     }
     if (library != null) name = _mangleName(name, library._reflectee);
     return new internal.Symbol.unvalidated(name);
   }
 
   static _mangleName(String name, _MirrorReference lib)
       native "Mirrors_mangleName";
 }