include.php

См. документацию.

<?php
 
use Bitrix\Main\Loader;
 
Loader::registerAutoLoadClasses(
    'highloadblock',
    [
        'CIBlockPropertyDirectory' => 'classes/general/prop_directory.php',
        'CUserTypeHlblock' => 'classes/general/cusertypehlblock.php',
    ]
);