Make JSFunction::BodyDescriptor the only single place that knows how to iterate JSFunction's body.

src/heap/objects-visiting.cc

 // Copyright 2011 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/heap/objects-visiting.h"
 
 #include "src/heap/mark-compact-inl.h"
 #include "src/heap/objects-visiting-inl.h"
 
 namespace v8 {
@@ skipping 220 matching lines @@
     case JS_REGEXP_TYPE:
     case JS_GLOBAL_PROXY_TYPE:
     case JS_GLOBAL_OBJECT_TYPE:
     case JS_MESSAGE_OBJECT_TYPE:
       JSObject::BodyDescriptor::IterateBody(this, object_size, v);
       break;
     case JS_ARRAY_BUFFER_TYPE:
       JSArrayBuffer::JSArrayBufferIterateBody(this, v);
       break;
     case JS_FUNCTION_TYPE:
-      reinterpret_cast<JSFunction*>(this)
-          ->JSFunctionIterateBody(object_size, v);
+      JSFunction::BodyDescriptor::IterateBody(this, object_size, v);
       break;
     case ODDBALL_TYPE:
       Oddball::BodyDescriptor::IterateBody(this, v);
       break;
     case JS_PROXY_TYPE:
       JSProxy::BodyDescriptor::IterateBody(this, v);
       break;
     case JS_FUNCTION_PROXY_TYPE:
       JSFunctionProxy::BodyDescriptor::IterateBody(this, v);
       break;
@@ skipping 237 matching lines @@
 };
 
 
 template Object* VisitWeakList<Context>(Heap* heap, Object* list,
                                         WeakObjectRetainer* retainer);
 
 template Object* VisitWeakList<AllocationSite>(Heap* heap, Object* list,
                                                WeakObjectRetainer* retainer);
 }  // namespace internal
 }  // namespace v8