LibWeb: Don't use C++ name for error messages in generated bindings

Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp

@@ -2735,8 +2735,7 @@ static JS::ThrowCompletionOr<@fully_qualified_name@*> impl_from(JS::VM& vm)
 
         generator.append(R"~~~(
     if (!is<@fully_qualified_name@>(this_object))
-        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "@fully_qualified_name@");
-
+        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "@name@");
     return static_cast<@fully_qualified_name@*>(this_object);
 }
 )~~~");
@@ -3032,7 +3031,7 @@ static JS::ThrowCompletionOr<@fully_qualified_name@*> impl_from(JS::VM& vm)
 {
     auto* this_object = TRY(vm.this_value().to_object(vm));
     if (!is<@fully_qualified_name@>(this_object))
-        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "@fully_qualified_name@");
+        return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "@name@");
     return static_cast<@fully_qualified_name@*>(this_object);
 }