try {
    // Пример ошибки, которая в php 7.2 вызовет ошибку уровня E_WARNING
    $c = count(null);
} catch (RuntimeException $e) {
    // Сработает на E_WARNING: Warning: count(): Parameter must be an array or an object that implements Countable
}

PHP 7.2.7 (cli) (built: Jul  3 2018 02:04:37) ( NTS MSVC15 (Visual C++ 2017) x64 )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Xdebug v2.7.0alpha2-dev, Copyright (c) 2002-2018, by Derick Rethans
    with Zend OPcache v7.2.7, Copyright (c) 1999-2018, by Zend Technologies

error_reporting = E_ALL & ~E_NOTICE & ~E_DEPRECATED & ~E_STRICT & ~E_WARNING