Fixes bug in scoping for generic methods.

pkg/compiler/lib/src/tree/unparser.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 '../tokens/token.dart' show Token;
 import '../tokens/token_constants.dart' as Tokens
     show IDENTIFIER_TOKEN, KEYWORD_TOKEN, PLUS_TOKEN;
 import '../util/util.dart';
 import 'nodes.dart';
 
@@ skipping 242 matching lines @@
     }
     if (node.returnType != null && !stripTypes) {
       visit(node.returnType);
       write(' ');
     }
     if (node.getOrSet != null) {
       write(node.getOrSet.value);
       write(' ');
     }
     unparseFunctionName(node.name);
+    visit(node.typeVariables);
     visit(node.parameters);
     if (node.initializers != null) {
       space();
       write(':');
       space();
       unparseNodeListFrom(node.initializers, node.initializers.nodes,
           spaces: true);
     }
     if (node.asyncModifier != null) {
       if (node.getOrSet != null) {
@@ skipping 623 matching lines @@
   }
 
   visitStatement(Statement node) {
     throw 'internal error'; // Should not be called.
   }
 
   visitStringNode(StringNode node) {
     throw 'internal error'; // Should not be called.
   }
 }