Keep prototype maps in dictionary mode until ICs see them

src/builtins.cc

 // Copyright 2012 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/builtins.h"
 
 #include "src/api-arguments.h"
 #include "src/api-natives.h"
 #include "src/api.h"
 #include "src/base/once.h"
@@ skipping 254 matching lines @@
 
 inline bool HasOnlySimpleReceiverElements(Isolate* isolate,
                                           JSObject* receiver) {
   // Check that we have no accessors on the receiver's elements.
   if (!HasSimpleElements(receiver)) return false;
   return PrototypeHasNoElements(isolate, receiver);
 }
 
 inline bool HasOnlySimpleElements(Isolate* isolate, JSReceiver* receiver) {
   DisallowHeapAllocation no_gc;
-  PrototypeIterator iter(isolate, receiver,
-                         PrototypeIterator::START_AT_RECEIVER);
+  PrototypeIterator iter(isolate, receiver, kStartAtReceiver);
   for (; !iter.IsAtEnd(); iter.Advance()) {
     if (iter.GetCurrent()->IsJSProxy()) return false;
     JSObject* current = iter.GetCurrent<JSObject>();
     if (!HasSimpleElements(current)) return false;
   }
   return true;
 }
 
 // Returns |false| if not applicable.
 MUST_USE_RESULT
@@ skipping 5647 matching lines @@
 BUILTIN_LIST_T(DEFINE_BUILTIN_ACCESSOR_T)
 BUILTIN_LIST_H(DEFINE_BUILTIN_ACCESSOR_H)
 BUILTIN_LIST_DEBUG_A(DEFINE_BUILTIN_ACCESSOR_A)
 #undef DEFINE_BUILTIN_ACCESSOR_C
 #undef DEFINE_BUILTIN_ACCESSOR_A
 #undef DEFINE_BUILTIN_ACCESSOR_T
 #undef DEFINE_BUILTIN_ACCESSOR_H
 
 }  // namespace internal
 }  // namespace v8