[php-src] Issue #22123: Exit in register_shutdown_function overwrites exit code since PHP8.4

Issue: https://github.com/php/php-src/issues/22123 Author: PrinsFrank ### Description The following code: ```php <?php declare(strict_types=1); register_shutdown_function(static function () { exit; // prevent further shutdown handlers from being called }); exit(1); ``` https://3v4l.org/C9oKE#v Results in exit code 0 since PHP8.4, while it returned the original exit code 1 in previous versions. According to [the documentation](https://www.php.net/manual/en/function.register-shutdown-function.php), this is should be a valid way to stop shutdown_function propagation: > If you call [exit()](https://www.php.net/manual/en/function.exit.php) within one registered > shutdown function, processing will stop completely and no other registered shutdown functions will > be called. ### PHP Version ```plain 8.4.1 - 8.4.18, 8.5.0 - 8.5.3 (from above sample from 3v4l.org) ``` ### Operating System _No response_