[php-src] Issue #10825: Using null coalesce operator seems to loose variables passed as reference

Issue: https://github.com/php/php-src/issues/10825 Author: dsentker24 ### Description The following code: ```php <?php $arr = [ 'deep' => [ 'bar' => 'foo', ], ]; foreach($arr['deep'] ?? [] as &$value) { $value = 'x'; } var_dump('x' === $arr['deep']['bar']); ``` Resulted in this output: ``` bool(false) ``` But I expected this output instead: ``` bool(true) ``` If you use a reference to an array in a foreach, the reference is lost as soon as you use the null coalesce operator to check for existence. ### PHP Version PHP 7.x, PHP 8.x ### Operating System _No response_