Update dart:mirrors to use Symbol.

dart/runtime/lib/function_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 Function {
   static _apply(List arguments, List names)
       native "Function_apply";
 
   /* patch */ static apply(Function function,
                            List positionalArguments,
                            [Map<Symbol, dynamic> namedArguments]) {
     int numPositionalArguments = 1 +  // Function is first implicit argument.
         (positionalArguments != null ? positionalArguments.length : 0);
     int numNamedArguments = namedArguments != null ? namedArguments.length : 0;
     int numArguments = numPositionalArguments + numNamedArguments;
     List arguments = new List(numArguments);
     arguments[0] = function;
     arguments.setRange(1, numPositionalArguments, positionalArguments);
     List names = new List(numNamedArguments);
     int argumentIndex = numPositionalArguments;
     int nameIndex = 0;
     if (numNamedArguments > 0) {
       namedArguments.forEach((name, value) {
         arguments[argumentIndex++] = value;
-        names[nameIndex++] = name._name;
+        names[nameIndex++] = _symbol_dev.Symbol.getName(name);
       });
     }
     return _apply(arguments, names);
   }
 }