Use DescriptorArray when checking if an object has a property

src/objects.cc

 // Copyright 2013 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 <iomanip>
 #include <sstream>
 
 #include "src/accessors.h"
@@ skipping 12717 matching lines @@
   if (result.IsEmpty()) return MaybeHandle<JSObject>();
   DCHECK(v8::Utils::OpenHandle(*result)->IsJSArray() ||
          v8::Utils::OpenHandle(*result)->HasSloppyArgumentsElements());
   // Rebox before returning.
   return handle(*v8::Utils::OpenHandle(*result), isolate);
 }
 
 
 Maybe<bool> JSObject::HasRealNamedProperty(Handle<JSObject> object,
                                            Handle<Name> name) {
+  DescriptorArray* desc = object->map()->instance_descriptors();
+  if (!desc->IsEmpty()) {
+    int there = desc->SearchWithCache(*name, object->map());
+    return Just(there != desc->kNotFound);
+  }
+
   LookupIterator it = LookupIterator::PropertyOrElement(
       name->GetIsolate(), object, name, LookupIterator::OWN_SKIP_INTERCEPTOR);
   Maybe<PropertyAttributes> maybe_result = GetPropertyAttributes(&it);
   if (!maybe_result.IsJust()) return Nothing<bool>();
   return Just(it.IsFound());
 }
 
 
 Maybe<bool> JSObject::HasRealElementProperty(Handle<JSObject> object,
                                              uint32_t index) {
@@ skipping 2952 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