[php-src] Issue #21986: Segfault during `->getContent()` on a `phar` with recursive symlinks

Issue: https://github.com/php/php-src/issues/21986
Author: edorian

### Description

The following code:

```php
<?php

$dir = '/tmp/phar_test';
mkdir($dir . '/content', 0777, true);
chdir($dir . '/content');
symlink('b.txt', 'a.txt');
symlink('a.txt', 'b.txt');
exec("tar cf $dir/test.tar a.txt b.txt");
$phar = new PharData("$dir/test.tar");
$phar['a.txt']->getContent();
```

Resulted in this output:
```
[1]    6676 segmentation fault  php reproduce.php
```

But I expected this output instead:
```
Some kind of error
```


### PHP Version

```plain
PHP 8.5.6 (cli) (built: May  5 2026 21:19:36) (NTS)
Copyright (c) The PHP Group
Built by Homebrew
Zend Engine v4.5.6, Copyright (c) Zend Technologies
    with Zend OPcache v8.5.6, Copyright (c), by Zend Technologies
```

### Operating System

macOS