Description:
------------
Using docker image php:8.0.0rc1-fpm-alpine3.12;

```
Fatal error: Uncaught Error: Call to undefined method SplFixedArray::rewind() in /app/test.php:4
Stack trace:
#0 {main}
  thrown in /app/test.php on line 4
```

Not sure if removed by design in PHP8, but it is not in the docs.

Test script:
---------------
```
<?php

$foo = new \SplFixedArray();
$foo->rewind();
```