Keep prototype maps in dictionary mode until ICs see them

src/runtime/runtime-array.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/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/code-stubs.h"
 #include "src/conversions-inl.h"
 #include "src/elements.h"
@@ skipping 185 matching lines @@
   if (!array->elements()->IsDictionary()) {
     CHECK(array->HasFastSmiOrObjectElements() ||
           array->HasFastDoubleElements());
     uint32_t actual_length = static_cast<uint32_t>(array->elements()->length());
     return *isolate->factory()->NewNumberFromUint(Min(actual_length, length));
   }
 
   KeyAccumulator accumulator(isolate, KeyCollectionMode::kOwnOnly,
                              ALL_PROPERTIES);
   // No need to separate prototype levels since we only get element keys.
-  for (PrototypeIterator iter(isolate, array,
-                              PrototypeIterator::START_AT_RECEIVER);
+  for (PrototypeIterator iter(isolate, array, kStartAtReceiver);
        !iter.IsAtEnd(); iter.Advance()) {
     if (PrototypeIterator::GetCurrent(iter)->IsJSProxy() ||
         PrototypeIterator::GetCurrent<JSObject>(iter)
             ->HasIndexedInterceptor()) {
       // Bail out if we find a proxy or interceptor, likely not worth
       // collecting keys in that case.
       return *isolate->factory()->NewNumberFromUint(length);
     }
     Handle<JSObject> current = PrototypeIterator::GetCurrent<JSObject>(iter);
     accumulator.CollectOwnElementIndices(array, current);
@@ skipping 226 matching lines @@
 
   // On success, return the fixed array elements.
   return object->elements();
 }
 
 
 RUNTIME_FUNCTION(Runtime_HasComplexElements) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
-  for (PrototypeIterator iter(isolate, array,
-                              PrototypeIterator::START_AT_RECEIVER);
+  for (PrototypeIterator iter(isolate, array, kStartAtReceiver);
        !iter.IsAtEnd(); iter.Advance()) {
     if (PrototypeIterator::GetCurrent(iter)->IsJSProxy()) {
       return isolate->heap()->true_value();
     }
     Handle<JSObject> current = PrototypeIterator::GetCurrent<JSObject>(iter);
     if (current->HasIndexedInterceptor()) {
       return isolate->heap()->true_value();
     }
     if (!current->HasDictionaryElements()) continue;
     if (current->element_dictionary()->HasComplexElements()) {
@@ skipping 38 matching lines @@
 RUNTIME_FUNCTION(Runtime_ArraySpeciesConstructor) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, original_array, 0);
   RETURN_RESULT_OR_FAILURE(
       isolate, Object::ArraySpeciesConstructor(isolate, original_array));
 }
 
 }  // namespace internal
 }  // namespace v8