ArrayObject::__construct Replace tag and implement → extend + CS

[mmalferov]

No description provided.

[mmalferov]

Maybe create a separate pull request that corrects the categorical requirement to extend the iterator class?

The class must extend the ArrayIterator class.

To:

The class must belong to or extend the ArrayIterator class.

<?php

$array = [];

// The third argument do not extends the ArrayIterator class, while "MUST"
$arrayObject = new ArrayObject($array, 0, 'ArrayIterator');```

[Girgias]

I suppose

must be a subclass (or subtype) of ArrayIterator
would work better?