Use Null as "no accessor" in AccessorPair instead of TheHole

src/objects.cc

 // Copyright 2015 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 9709 matching lines @@
     }
 
     Handle<Object> maybe_pair(old_descriptors->GetValue(descriptor), isolate);
     if (!maybe_pair->IsAccessorPair()) {
       return Map::Normalize(map, mode, "AccessorsOverwritingNonPair");
     }
 
     Object* current = Handle<AccessorPair>::cast(maybe_pair)->get(component);
     if (current == *accessor) return map;
 
-    if (!current->IsTheHole()) {
+    if (!current->IsNull()) {
       return Map::Normalize(map, mode, "AccessorsOverwritingAccessors");
     }
 
     pair = AccessorPair::Copy(Handle<AccessorPair>::cast(maybe_pair));
   } else if (map->NumberOfOwnDescriptors() >= kMaxNumberOfDescriptors ||
              map->TooManyFastProperties(CERTAINLY_NOT_STORE_FROM_KEYED)) {
     return Map::Normalize(map, CLEAR_INOBJECT_PROPERTIES, "TooManyAccessors");
   } else {
     pair = isolate->factory()->NewAccessorPair();
   }
@@ skipping 593 matching lines @@
 
 Handle<Object> AccessorPair::GetComponent(Handle<AccessorPair> accessor_pair,
                                           AccessorComponent component) {
   Object* accessor = accessor_pair->get(component);
   if (accessor->IsFunctionTemplateInfo()) {
     return ApiNatives::InstantiateFunction(
                handle(FunctionTemplateInfo::cast(accessor)))
         .ToHandleChecked();
   }
   Isolate* isolate = accessor_pair->GetIsolate();
-  if (accessor->IsTheHole()) {
+  if (accessor->IsNull()) {
     return isolate->factory()->undefined_value();
   }
   return handle(accessor, isolate);
 }
 
 Handle<DeoptimizationInputData> DeoptimizationInputData::New(
     Isolate* isolate, int deopt_entry_count, PretenureFlag pretenure) {
   return Handle<DeoptimizationInputData>::cast(
       isolate->factory()->NewFixedArray(LengthFor(deopt_entry_count),
                                         pretenure));
@@ skipping 8477 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8