Lazily compute boundfunction .name and .length if possible

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/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 1687 matching lines @@
   {  // --- B o u n d F u n c t i o n
     Handle<Map> map =
         factory->NewMap(JS_BOUND_FUNCTION_TYPE, JSBoundFunction::kSize);
     map->set_is_callable();
     Map::SetPrototype(map, empty_function);
 
     PropertyAttributes roc_attribs =
         static_cast<PropertyAttributes>(DONT_ENUM | READ_ONLY);
     Map::EnsureDescriptorSlack(map, 2);
 
+    Handle<AccessorInfo> bound_length =
+        Accessors::BoundFunctionLengthInfo(isolate, roc_attribs);
     {  // length
-      DataDescriptor d(factory->length_string(), JSBoundFunction::kLengthIndex,
-                       roc_attribs, Representation::Tagged());
+      AccessorConstantDescriptor d(factory->length_string(), bound_length,
+                                   roc_attribs);
       map->AppendDescriptor(&d);
     }
-    {  // name
-      DataDescriptor d(factory->name_string(), JSBoundFunction::kNameIndex,
-                       roc_attribs, Representation::Tagged());
+    Handle<AccessorInfo> bound_name =
+        Accessors::BoundFunctionNameInfo(isolate, roc_attribs);
+    {  // length
+      AccessorConstantDescriptor d(factory->name_string(), bound_name,
+                                   roc_attribs);
       map->AppendDescriptor(&d);
     }
-
-    map->SetInObjectProperties(2);
+    map->SetInObjectProperties(0);
     native_context()->set_bound_function_without_constructor_map(*map);
 
     map = Map::Copy(map, "IsConstructor");
     map->set_is_constructor(true);
     native_context()->set_bound_function_with_constructor_map(*map);
   }
 
   {  // --- sloppy arguments map
     // Make sure we can recognize argument objects at runtime.
     // This is done by introducing an anonymous function with
@@ skipping 1884 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8