Mark maps having a hidden prototype rather than maps of hidden prototypes.

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 937 matching lines @@
 #endif
   } else {
     Handle<FunctionTemplateInfo> js_global_object_constructor(
         FunctionTemplateInfo::cast(js_global_object_template->constructor()));
     js_global_object_function = ApiNatives::CreateApiFunction(
         isolate(), js_global_object_constructor, factory()->the_hole_value(),
         ApiNatives::GlobalObjectType);
   }
 
   js_global_object_function->initial_map()->set_is_prototype_map(true);
-  js_global_object_function->initial_map()->set_is_hidden_prototype();
   js_global_object_function->initial_map()->set_dictionary_map(true);
   Handle<JSGlobalObject> global_object =
       factory()->NewJSGlobalObject(js_global_object_function);
 
   // Step 2: (re)initialize the global proxy object.
   Handle<JSFunction> global_proxy_function;
   if (global_proxy_template.IsEmpty()) {
     Handle<String> name = Handle<String>(heap()->empty_string());
     Handle<Code> code = isolate()->builtins()->Illegal();
     global_proxy_function = factory()->NewFunction(
         name, code, JS_GLOBAL_PROXY_TYPE, JSGlobalProxy::kSize);
   } else {
     Handle<ObjectTemplateInfo> data =
         v8::Utils::OpenHandle(*global_proxy_template);
     Handle<FunctionTemplateInfo> global_constructor(
             FunctionTemplateInfo::cast(data->constructor()));
     global_proxy_function = ApiNatives::CreateApiFunction(
         isolate(), global_constructor, factory()->the_hole_value(),
         ApiNatives::GlobalProxyType);
   }
-
   Handle<String> global_name = factory()->global_string();
   global_proxy_function->shared()->set_instance_class_name(*global_name);
   global_proxy_function->initial_map()->set_is_access_check_needed(true);
+  global_proxy_function->initial_map()->set_has_hidden_prototype(true);
 
   // Set global_proxy.__proto__ to js_global after ConfigureGlobalObjects
   // Return the global proxy.
 
   factory()->ReinitializeJSGlobalProxy(global_proxy, global_proxy_function);
   return global_object;
 }
 
 
 void Genesis::HookUpGlobalProxy(Handle<JSGlobalObject> global_object,
@@ skipping 2643 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8