Clone and link all tokens in AstCloner.

pkg/analyzer/lib/src/dart/ast/ast.dart

 // Copyright (c) 2014, 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 analyzer.src.dart.ast.ast;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 1939 matching lines @@
     ..add(_superclass)
     ..add(_withClause)
     ..add(_implementsClause)
     ..add(semicolon);
 
   @override
   ClassElement get element =>
       _name != null ? (_name.staticElement as ClassElement) : null;
 
   @override
+  Token get firstTokenAfterCommentAndMetadata {
+    if (abstractKeyword != null) {
+      return abstractKeyword;
+    }
+    return typedefKeyword;
+  }
+
+  @override
   ImplementsClause get implementsClause => _implementsClause;
 
   @override
   void set implementsClause(ImplementsClause implementsClause) {
     _implementsClause = _becomeParentOf(implementsClause);
   }
 
   @override
   bool get isAbstract => abstractKeyword != null;
 
@@ skipping 8826 matching lines @@
   }
 
   @override
   accept(AstVisitor visitor) => visitor.visitYieldStatement(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _safelyVisitChild(_expression, visitor);
   }
 }