handle the special snowflakes that are Integer Indexed Exotic objects

src/lookup-inl.h

 // Copyright 2014 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.
 
 #ifndef V8_LOOKUP_INL_H_
 #define V8_LOOKUP_INL_H_
 
 #include "src/lookup.h"
 
 namespace v8 {
@@ skipping 26 matching lines @@
   DisallowHeapAllocation no_gc;
   switch (state_) {
     case NOT_FOUND:
       if (map->IsJSProxyMap()) return JSPROXY;
       if (map->is_access_check_needed() &&
           !isolate_->IsInternallyUsedPropertyName(name_)) {
         return ACCESS_CHECK;
       }
     // Fall through.
     case ACCESS_CHECK:
+      if (exotic_index_state_ != ExoticIndexState::kNoIndex &&
+          IsIntegerIndexedExotic(holder)) {
+        has_property_ = true;
+        return INTEGER_INDEXED_EXOTIC;
+      }
       if (check_interceptor() && map->has_named_interceptor()) {
         return INTERCEPTOR;
       }
     // Fall through.
     case INTERCEPTOR:
       if (map->is_dictionary_map()) {
         NameDictionary* dict = JSObject::cast(holder)->property_dictionary();
         number_ = dict->FindEntry(name_);
         if (number_ == NameDictionary::kNotFound) return NOT_FOUND;
         property_details_ = dict->DetailsAt(number_);
@@ skipping 11 matching lines @@
       has_property_ = true;
       switch (property_details_.kind()) {
         case v8::internal::kData:
           return DATA;
         case v8::internal::kAccessor:
           return ACCESSOR;
       }
     case ACCESSOR:
     case DATA:
       return NOT_FOUND;
+    case INTEGER_INDEXED_EXOTIC:
     case JSPROXY:
     case TRANSITION:
       UNREACHABLE();
   }
   UNREACHABLE();
   return state_;
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_LOOKUP_INL_H_