Parse type variables of local functions before return type.

pkg/front_end/lib/src/fasta/parser/listener.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.
 
 library fasta.parser.listener;
 
 import '../../scanner/token.dart' show Token, TokenType;
 
 import '../fasta_codes.dart' show Message;
 
@@ skipping 263 matching lines @@
   /// - Name
   /// - Type variables
   /// - Formals
   /// - Initializers
   /// - Async modifier
   /// - Function body (block or arrow expression).
   void endNamedFunctionExpression(Token endToken) {
     logEvent("NamedFunctionExpression");
   }
 
-  /// Handle the beginning of a local function declaration.
+  /// Handle the beginning of a local function declaration.  Substructures:
+  /// - Type variables
   void beginLocalFunctionDeclaration(Token token) {}
 
   /// A function declaration.
   ///
   /// Substructures:
   /// - Modifiers
   /// - Return type
   /// - Name
   /// - Type variables
   /// - Formals
@@ skipping 806 matching lines @@
   void discardTypeReplacedWithCommentTypeAssign() {}
 
   /// Creates a new synthetic token whose `next` pointer points to [next].
   ///
   /// If [next] is `null`, `null` is returned.
   Token newSyntheticToken(Token next) {
     if (next == null) return null;
     return new Token(TokenType.RECOVERY, next.charOffset)..next = next;
   }
 }