Keep prototype maps in dictionary mode until ICs see them

src/factory.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/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/conversions.h"
@@ skipping 78 matching lines @@
   return result;
 }
 
 
 Handle<PrototypeInfo> Factory::NewPrototypeInfo() {
   Handle<PrototypeInfo> result =
       Handle<PrototypeInfo>::cast(NewStruct(PROTOTYPE_INFO_TYPE));
   result->set_prototype_users(WeakFixedArray::Empty());
   result->set_registry_slot(PrototypeInfo::UNREGISTERED);
   result->set_validity_cell(Smi::FromInt(0));
+  result->set_bit_field(0);
   return result;
 }
 
 
 Handle<SloppyBlockWithEvalContextExtension>
 Factory::NewSloppyBlockWithEvalContextExtension(
     Handle<ScopeInfo> scope_info, Handle<JSObject> extension) {
   DCHECK(scope_info->is_declaration_scope());
   Handle<SloppyBlockWithEvalContextExtension> result =
       Handle<SloppyBlockWithEvalContextExtension>::cast(
@@ skipping 2285 matching lines @@
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 }  // namespace internal
 }  // namespace v8