Symfony polyfill backporting some PHP 7.0+ features to lower PHP versions

 This component provides features unavailable in releases prior to PHP 7.0:
 .
  * intdiv
  * preg_replace_callback_array
  * error_clear_last
  * random_bytes and random_int (via php-random-compat)
  * *Error throwable classes
 .
 Compatibility notes:
 .
 To write portable code between PHP5 and PHP7, some care must be taken:
  * `\*Error` exceptions must be caught before `\Exception`;
  * after calling `error_clear_last()`, the result of
    `$e = error_get_last()` must be verified using
    `isset($e['message'][0])` instead of `null === $e`.
 .
 The Symfony Polyfill project backports features found in the latest PHP
 versions and provides compatibility layers for some extensions and functions.
 It is intended to be used when portability across PHP versions and extensions
 is desired.
 .
 Symfony is a PHP framework, a set of tools and a development methodology.