Fastpath some spread-call desugaring.

src/bootstrapper.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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/ieee754.h"
 #include "src/code-stubs.h"
@@ skipping 1308 matching lines @@
   }
 
   {  // --- A r r a y I t e r a t o r ---
     Handle<JSObject> iterator_prototype(
         native_context()->initial_iterator_prototype());
 
     Handle<JSObject> array_iterator_prototype =
         factory->NewJSObject(isolate->object_function(), TENURED);
     JSObject::ForceSetPrototype(array_iterator_prototype, iterator_prototype);
 
+    native_context()->set_initial_array_iterator_prototype(
+        *array_iterator_prototype);
+
     JSObject::AddProperty(
         array_iterator_prototype, factory->to_string_tag_symbol(),
         factory->ArrayIterator_string(),
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY));
 
     Handle<JSFunction> next = InstallFunction(
         array_iterator_prototype, "next", JS_OBJECT_TYPE, JSObject::kHeaderSize,
         MaybeHandle<JSObject>(), Builtins::kArrayIteratorPrototypeNext);
 
     // Set the expected parameters for %ArrayIteratorPrototype%.next to 0 (not
@@ skipping 3204 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8