Use metadata annotation @patch for patch classes

runtime/lib/integers_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.
 // Dart core library.
 
 // VM implementation of int.
 
 import 'dart:_internal' as internal;
 
-patch class int {
+@patch class int {
 
-  /* patch */ const factory int.fromEnvironment(String name,
+  /* @patch */ const factory int.fromEnvironment(String name,
                                                 {int defaultValue})
       native "Integer_fromEnvironment";
 
 
   static int _tryParseSmi(String str, int first, int last) {
     assert(first <= last);
     var ix = first;
     var sign = 1;
     var c = str.codeUnitAt(ix);
     // Check for leading '+' or '-'.
@@ skipping 12 matching lines @@
     for (int i = ix; i <= last; i++) {
       var c = 0x30 ^ str.codeUnitAt(i);
       if (9 < c) {
         return null;
       }
       result = 10 * result + c;
     }
     return sign * result;
   }
 
-  /* patch */ static int parse(String source,
+  /* @patch */ static int parse(String source,
                                { int radix,
                                  int onError(String str) }) {
     if (source == null) throw new ArgumentError("The source must not be null");
     if (source.isEmpty) return _throwFormatException(onError, source, 0, radix);
     if (radix == null || radix == 10) {
       // Try parsing immediately, without trimming whitespace.
       int result = _tryParseSmi(source, 0, source.length - 1);
       if (result != null) return result;
     } else if (radix < 2 || radix > 36) {
       throw new RangeError("Radix $radix not in range 2..36");
@@ skipping 148 matching lines @@
      6,  594823321,  12,  353814783205469041,
      6,  729000000,  12,  531441000000000000,  /* radix: 30 */
      6,  887503681,  12,  787662783788549761,
      6, 1073741824,  12, 1152921504606846976,
      5,   39135393,  12, 1667889514952984961,
      5,   45435424,  12, 2386420683693101056,
      5,   52521875,  12, 3379220508056640625,  /* radix: 35 */
      5,   60466176,  11,  131621703842267136,
   ];
 }