Fastpath some spread-call desugaring.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index e484c80203fe6e9b4817c3215cc18ee95a7887e3..6b8acc41f64c69c9a1bb2eaca84a01be8c8dbb92 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -1326,6 +1326,9 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
         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(),