Lazily compute boundfunction .name and .length if possible

src/factory.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/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/conversions.h"
@@ skipping 1942 matching lines @@
   if (bound_args.length() == 0) {
     bound_arguments = empty_fixed_array();
   } else {
     bound_arguments = NewFixedArray(bound_args.length());
     for (int i = 0; i < bound_args.length(); ++i) {
       bound_arguments->set(i, *bound_args[i]);
     }
   }
 
   // Setup the map for the JSBoundFunction instance.
-  Handle<Map> map = handle(
-      target_function->IsConstructor()
-          ? isolate()->native_context()->bound_function_with_constructor_map()
-          : isolate()
-                ->native_context()
-                ->bound_function_without_constructor_map(),
-      isolate());
+  Handle<Map> map = target_function->IsConstructor()
+                        ? isolate()->bound_function_with_constructor_map()
+                        : isolate()->bound_function_without_constructor_map();
   if (map->prototype() != *prototype) {
     map = Map::TransitionToPrototype(map, prototype, REGULAR_PROTOTYPE);
   }
   DCHECK_EQ(target_function->IsConstructor(), map->is_constructor());
 
   // Setup the JSBoundFunction instance.
   Handle<JSBoundFunction> result =
       Handle<JSBoundFunction>::cast(NewJSObjectFromMap(map));
   result->set_bound_target_function(*target_function);
   result->set_bound_this(*bound_this);
   result->set_bound_arguments(*bound_arguments);
-  result->set_length(Smi::FromInt(0));
-  result->set_name(*undefined_value(), SKIP_WRITE_BARRIER);
   return result;
 }
 
 
 // ES6 section 9.5.15 ProxyCreate (target, handler)
 Handle<JSProxy> Factory::NewJSProxy(Handle<JSReceiver> target,
                                     Handle<JSReceiver> handler) {
   // Allocate the proxy object.
   Handle<Map> map;
   if (target->IsCallable()) {
@@ skipping 384 matching lines @@
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 }  // namespace internal
 }  // namespace v8