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 1332 matching lines @@
     // Set the length for the function to satisfy ECMA-262.
     next->shared()->set_length(0);
 
     Handle<JSFunction> array_iterator_function = CreateFunction(
         isolate, factory->ArrayIterator_string(),
         JS_FAST_ARRAY_VALUE_ITERATOR_TYPE, JSArrayIterator::kSize,
         array_iterator_prototype, Builtins::kIllegal);
     array_iterator_function->shared()->set_instance_class_name(
         isolate->heap()->ArrayIterator_string());
 
+    native_context()->set_initial_array_iterator_prototype(
+        *array_iterator_prototype);
+    native_context()->set_initial_array_iterator_prototype_map(
+        array_iterator_prototype->map());
+
     Handle<Map> initial_map(array_iterator_function->initial_map(), isolate);
 
 #define ARRAY_ITERATOR_LIST(V)                                              \
   V(TYPED_ARRAY, KEY, typed_array, key)                                     \
   V(FAST_ARRAY, KEY, fast_array, key)                                       \
   V(GENERIC_ARRAY, KEY, array, key)                                         \
   V(UINT8_ARRAY, KEY_VALUE, uint8_array, key_value)                         \
   V(INT8_ARRAY, KEY_VALUE, int8_array, key_value)                           \
   V(UINT16_ARRAY, KEY_VALUE, uint16_array, key_value)                       \
   V(INT16_ARRAY, KEY_VALUE, int16_array, key_value)                         \
@@ skipping 3197 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8