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 2805 matching lines @@
   // Handling of script id generation is in Heap::NextScriptId().
   set_last_script_id(Smi::FromInt(v8::UnboundScript::kNoScriptId));
   set_next_template_serial_number(Smi::kZero);
 
   // Allocate the empty script.
   Handle<Script> script = factory->NewScript(factory->empty_string());
   script->set_type(Script::TYPE_NATIVE);
   set_empty_script(*script);
 
   Handle<PropertyCell> cell = factory->NewPropertyCell();
-  cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
+  cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
   set_array_protector(*cell);
 
   cell = factory->NewPropertyCell();
   cell->set_value(the_hole_value());
   set_empty_property_cell(*cell);
 
   cell = factory->NewPropertyCell();
-  cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
+  cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
   set_has_instance_protector(*cell);
 
   Handle<Cell> is_concat_spreadable_cell = factory->NewCell(
-      handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate()));
+      handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_is_concat_spreadable_protector(*is_concat_spreadable_cell);
 
   Handle<Cell> species_cell = factory->NewCell(
-      handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate()));
+      handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_species_protector(*species_cell);
 
   cell = factory->NewPropertyCell();
-  cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
+  cell->set_value(Smi::FromInt(Isolate::kProtectorValid));
   set_string_length_protector(*cell);
 
   Handle<Cell> fast_array_iteration_cell = factory->NewCell(
-      handle(Smi::FromInt(Isolate::kArrayProtectorValid), isolate()));
+      handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
   set_fast_array_iteration_protector(*fast_array_iteration_cell);
 
+  Handle<Cell> array_iterator_cell = factory->NewCell(
+      handle(Smi::FromInt(Isolate::kProtectorValid), isolate()));
+  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 3603 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8