[builtins] Move more files into v8_builtins_generators source set

src/builtins/builtins-forin-gen.h

 
 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stub-assembler.h"
 
 namespace v8 {
 namespace internal {
 
@@ skipping 14 matching lines @@
   void CheckPrototypeEnumCache(Node* receiver, Node* map, Label* use_cache,
                                Label* use_runtime);
   // Check the cache validity for |receiver|. Branch to |use_cache| if
   // the cache is valid, otherwise branch to |use_runtime|.
   void CheckEnumCache(Node* receiver, Label* use_cache,
                       Label* nothing_to_iterate, Label* use_runtime);
 };
 
 }  // namespace internal
 }  // namespace v8