Fastpath some spread-call desugaring.

src/heap/heap.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/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 2822 matching lines @@
   set_is_concat_spreadable_protector(*is_concat_spreadable_cell);
 
   Handle<Cell> species_cell = factory->NewCell(
       handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate()));
   set_species_protector(*species_cell);
 
   cell = factory->NewPropertyCell();
   cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
   set_string_length_protector(*cell);
 
+  Handle<Cell> array_iterator_cell = factory->NewCell(
+      handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate()));

[Yang, 2016/11/14 10:17:19]

Can we name kArrayProtectorValid to kProtectorValid?

[petermarshall, 2016/11/14 12:52:50]

Sounds good to me.

+  set_array_iterator_protector(*array_iterator_cell);
+
   set_serialized_templates(empty_fixed_array());
 
   set_weak_stack_trace_list(Smi::kZero);
 
   set_noscript_shared_function_infos(Smi::kZero);
 
   // Initialize context slot cache.
   isolate_->context_slot_cache()->Clear();
 
   // Initialize descriptor cache.
@@ skipping 3602 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8