IDL: Add support for [Unscopeable] on attributes and methods

Source/bindings/templates/interface.h

Index: Source/bindings/templates/interface.h
diff --git a/Source/bindings/templates/interface.h b/Source/bindings/templates/interface.h
index 05b3eb5602c36067d8803813bd3c5dfc88fabda3..e25c423775a882d0f8f05096f04f9734d776d09d 100644
--- a/Source/bindings/templates/interface.h
+++ b/Source/bindings/templates/interface.h
@@ -158,11 +158,11 @@ public:
     static void installConditionallyEnabledProperties(v8::Local<v8::Object>, v8::Isolate*){% if has_conditional_attributes %};
     {% else %} { }
     {% endif %}
-    static void installConditionallyEnabledMethods(v8::Local<v8::Object>, v8::Isolate*){% if conditionally_enabled_methods %};
+    static void preparePrototypeObject(v8::Isolate*, v8::Local<v8::Object>){% if unscopeables or conditionally_enabled_methods %};
     {% else %} { }
     {% endif %}
     {% if has_partial_interface %}
-    {{exported}}static void updateWrapperTypeInfo(InstallTemplateFunction, InstallConditionallyEnabledMethodsFunction);
+    {{exported}}static void updateWrapperTypeInfo(InstallTemplateFunction, PreparePrototypeObjectFunction);
     {{exported}}static void install{{v8_class}}Template(v8::Local<v8::FunctionTemplate>, v8::Isolate*);
     {% for method in methods if method.overloads and method.overloads.has_partial_overloads %}
     {{exported}}static void register{{method.name | blink_capitalize}}MethodForPartialInterface(void (*)(const v8::FunctionCallbackInfo<v8::Value>&));