Description:
------------
This is very similar to https://bugs.php.net/bug.php?id=71731 - the only difference being that I am typecasting.

It seems when typecasting is used, offsetExists is never called. It doesn't matter whether I try to typecast to string or int.

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

$data = new class implements \ArrayAccess
{
    public function offsetExists($offset)
    {
        echo "offsetExists\n";
    }

    public function offsetGet($offset)
    {
        echo "offsetGet\n";
    }

    public function offsetSet($offset, $value)
    {
    }

    public function offsetUnset($offset)
    {
    }

};
echo "null coalescing operator:\n";
$data['foo'] ?? null;
echo "null coalescing operator (typecast):\n";
(int)$data['foo'] ?? null;


Expected result:
----------------
null coalescing operator:
offsetExists
null coalescing operator (typecast):
offsetExists

Actual result:
--------------
null coalescing operator:
offsetExists
null coalescing operator (typecast):
offsetGet