[runtime] Remove an obsolete path in PropertyCell code

Change-Id: I2c9f3ac81710b89543b392819a6cce03eaba6cae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2536639
Commit-Queue: Georg Neis <neis@chromium.org>
Auto-Submit: Georg Neis <neis@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71181}

src/objects/objects.cc

@@ -6393,20 +6393,9 @@ PropertyCellType PropertyCell::UpdatedType(Isolate* isolate,
                                            Handle<PropertyCell> cell,
                                            Handle<Object> value,
                                            PropertyDetails details) {
-  PropertyCellType type = details.cell_type();
   DCHECK(!value->IsTheHole(isolate));
-  if (cell->value().IsTheHole(isolate)) {
-    switch (type) {
-      // Only allow a cell to transition once into constant state.
-      case PropertyCellType::kUninitialized:
-        return TypeForUninitializedCell(isolate, value);
-      case PropertyCellType::kInvalidated:
-        return PropertyCellType::kMutable;
-      default:
-        UNREACHABLE();
-    }
-  }
-  switch (type) {
+  DCHECK(!cell->value().IsTheHole(isolate));
+  switch (details.cell_type()) {
     case PropertyCellType::kUndefined:
       return PropertyCellType::kConstant;
     case PropertyCellType::kConstant:
@@ -6428,20 +6417,12 @@ Handle<PropertyCell> PropertyCell::PrepareForValue(
     Handle<Object> value, PropertyDetails details) {
   DCHECK(!value->IsTheHole(isolate));
   Handle<PropertyCell> cell(dictionary->CellAt(entry), isolate);
+  CHECK(!cell->value().IsTheHole(isolate));
   const PropertyDetails original_details = cell->property_details();
   // Data accesses could be cached in ics or optimized code.
   bool invalidate =
       original_details.kind() == kData && details.kind() == kAccessor;
-  int index;
-  PropertyCellType old_type = original_details.cell_type();
-  // Preserve the enumeration index unless the property was deleted or never
-  // initialized.
-  if (cell->value().IsTheHole(isolate)) {
-    index = GlobalDictionary::NextEnumerationIndex(isolate, dictionary);
-    dictionary->set_next_enumeration_index(index + 1);
-  } else {
-    index = original_details.dictionary_index();
-  }
+  int index = original_details.dictionary_index();
   DCHECK_LT(0, index);
   details = details.set_index(index);
 
@@ -6464,7 +6445,7 @@ Handle<PropertyCell> PropertyCell::PrepareForValue(
   }
 
   // Deopt when transitioning from a constant type.
-  if (!invalidate && (old_type != new_type ||
+  if (!invalidate && (original_details.cell_type() != new_type ||
                       original_details.IsReadOnly() != details.IsReadOnly())) {
     cell->dependent_code().DeoptimizeDependentCodeGroup(
         DependentCode::kPropertyCellChangedGroup);