Bug report

Calling mb_strcut with the third parameter $length as null currently reports an error, that it should be int. According to the PHP documentation (If omitted or NULL is passed, extract all bytes to the end of the string), it supports also null.

Any ideas on how could I fix this?

Code snippet that reproduces the problem

Reproducer here: https://phpstan.org/r/01bc9ce6-2769-4987-a5d8-940b73e30130

Expected output

PHPStan should not report any errors if passing null as $length.