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

src/ic/ic.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/ic/ic.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/arguments.h"
 #include "src/base/bits.h"
@@ skipping 1675 matching lines @@
 
 
 Handle<Code> StoreIC::CompileHandler(LookupIterator* lookup,
                                      Handle<Object> value,
                                      CacheHolderFlag cache_holder) {
   DCHECK_NE(LookupIterator::JSPROXY, lookup->state());
 
   // This is currently guaranteed by checks in StoreIC::Store.
   Handle<JSObject> receiver = Handle<JSObject>::cast(lookup->GetReceiver());
   Handle<JSObject> holder = lookup->GetHolder<JSObject>();
-  DCHECK(!receiver->IsAccessCheckNeeded() ||
-         isolate()->IsInternallyUsedPropertyName(lookup->name()));
+  DCHECK(!receiver->IsAccessCheckNeeded() || lookup->name()->IsPrivate());
 
   switch (lookup->state()) {
     case LookupIterator::TRANSITION: {
       auto store_target = lookup->GetStoreTarget();
       if (store_target->IsJSGlobalObject()) {
         // TODO(dcarney): this currently just deopts. Use the transition cell.
         auto cell = isolate()->factory()->NewPropertyCell();
         cell->set_value(*value);
         auto code = PropertyCellStoreHandler(
             isolate(), store_target, Handle<JSGlobalObject>::cast(store_target),
@@ skipping 1245 matching lines @@
     KeyedLoadICNexus nexus(vector, vector_slot);
     KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate, &nexus);
     ic.UpdateState(receiver, key);
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   }
 
   return *result;
 }
 }  // namespace internal
 }  // namespace v8