[es6] Reintroduce the instanceof operator in the backends.

src/lookup.cc

 // 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.
 
 #include "src/lookup.h"
 
 #include "src/bootstrapper.h"
 #include "src/deoptimizer.h"
 #include "src/elements.h"
 #include "src/field-type.h"
@@ skipping 173 matching lines @@
     // Setting the Symbol.species property of any Array constructor invalidates
     // the species protector
     if (isolate_->IsInAnyContext(*holder_, Context::ARRAY_FUNCTION_INDEX)) {
       isolate_->CountUsage(
           v8::Isolate::UseCounterFeature::kArraySpeciesModified);
       isolate_->InvalidateArraySpeciesProtector();
     }
   } else if (*name_ == heap()->is_concat_spreadable_symbol()) {
     if (!isolate_->IsIsConcatSpreadableLookupChainIntact()) return;
     isolate_->InvalidateIsConcatSpreadableProtector();
+  } else if (*name_ == heap()->has_instance_symbol()) {
+    if (!isolate_->IsHasInstanceLookupChainIntact()) return;
+    isolate_->InvalidateHasInstanceProtector();
   }
 }
 
 void LookupIterator::PrepareForDataProperty(Handle<Object> value) {
   DCHECK(state_ == DATA || state_ == ACCESSOR);
   DCHECK(HolderIsReceiverOrHiddenPrototype());
 
   Handle<JSObject> holder = GetHolder<JSObject>();
 
   if (IsElement()) {
@@ skipping 546 matching lines @@
     case v8::internal::kAccessor:
       return ACCESSOR;
   }
 
   UNREACHABLE();
   return state_;
 }
 
 }  // namespace internal
 }  // namespace v8