merge class extensions from patch files

test/generated_sdk/lib/core/function.dart

 // Copyright (c) 2011, 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.
 
 part of dart.core;
 
 /**
  * The base class for all function types.
  *
  * A function value, or an instance of a class with a "call" method, is a
@@ skipping 50 matching lines @@
    *   not necessarily identical, function values.
    *
    * Function expressions never give rise to equal function objects. Each time
    * a function expression is evaluated, it creates a new closure value that
    * is not known to be equal to other closures created by the same expression.
    *
    * Classes implementing `Function` by having a `call` method should have their
    * own `operator==` and `hashCode` depending on the object.
    */
   bool operator==(Object other);
+
+  static Map<String, dynamic> _toMangledNames(
+      Map<Symbol, dynamic> namedArguments) {
+    Map<String, dynamic> result = {};
+    namedArguments.forEach((symbol, value) {
+      result[_symbolToString(symbol)] = value;
+    });
+    return result;
+  }
 }