[runtime] Replace hidden_string with a 0-hash-code private symbol

src/isolate.cc

 // Copyright 2012 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/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 764 matching lines @@
     data = handle(access_check_info->data(), this);
   }
 
   // Leaving JavaScript.
   VMState<EXTERNAL> state(this);
   thread_local_top()->failed_access_check_callback_(
       v8::Utils::ToLocal(receiver), v8::ACCESS_HAS, v8::Utils::ToLocal(data));
 }
 
 
-bool Isolate::IsInternallyUsedPropertyName(Handle<Object> name) {
-  if (name->IsSymbol()) {
-    return Handle<Symbol>::cast(name)->is_private();
-  }
-  return name.is_identical_to(factory()->hidden_string());
-}
-
-
 bool Isolate::MayAccess(Handle<Context> accessing_context,
                         Handle<JSObject> receiver) {
   DCHECK(receiver->IsJSGlobalProxy() || receiver->IsAccessCheckNeeded());
 
   // Check for compatibility between the security tokens in the
   // current lexical context and the accessed object.
 
   // During bootstrapping, callback functions are not enabled yet.
   if (bootstrapper()->IsActive()) return true;
   {
@@ skipping 2062 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8