[turbofan] Don't constant-fold ACCESSOR properties.

src/compiler/js-native-context-specialization.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/compiler/js-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 1099 matching lines @@
     Type* const field_type = access_info.field_type();
     MachineRepresentation const field_representation =
         access_info.field_representation();
     if (access_mode == AccessMode::kLoad) {
       if (access_info.holder().ToHandle(&holder)) {
         receiver = jsgraph()->Constant(holder);
       }
       // Optimize immutable property loads.
       HeapObjectMatcher m(receiver);
       if (m.HasValue() && m.Value()->IsJSObject()) {
+        // TODO(ishell): Use something simpler like
+        //
+        // Handle<Object> value =
+        //     JSObject::FastPropertyAt(Handle<JSObject>::cast(m.Value()),
+        //                              Representation::Tagged(), field_index);
+        //
+        // here, once we have the immutable bit in the access_info.
+
         // TODO(turbofan): Given that we already have the field_index here, we
         // might be smarter in the future and not rely on the LookupIterator,
         // but for now let's just do what Crankshaft does.
         LookupIterator it(m.Value(), name,
                           LookupIterator::OWN_SKIP_INTERCEPTOR);
-        if (it.IsFound() && it.IsReadOnly() && !it.IsConfigurable()) {
+        if (it.state() == LookupIterator::DATA && it.IsReadOnly() &&
+            !it.IsConfigurable()) {
           Node* value = jsgraph()->Constant(JSReceiver::GetDataProperty(&it));
           return ValueEffectControl(value, effect, control);
         }
       }
     }
     Node* storage = receiver;
     if (!field_index.is_inobject()) {
       storage = effect = graph()->NewNode(
           simplified()->LoadField(AccessBuilder::ForJSObjectProperties()),
           storage, effect, control);
@@ skipping 821 matching lines @@
   return jsgraph()->javascript();
 }
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8