Description:
------------
In PHP < 8.0 it was possible to make an argument nullable without the question mark if the default value is null. This works fine if the variable is directly null, but not when the default value is an CONST with a null value

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

declare(strict_types=1);

const ALLOW_ANY = null;

var_dump(ALLOW_ANY);

function foo(array $baz = ALLOW_ANY)
{
    return true;
}

var_dump(foo(NULL));

Expected result:
----------------
NULL
bool(true)

Actual result:
--------------
NULL

Fatal error: Uncaught TypeError: foo(): Argument #1 ($baz) must be of type array, null given, called in /in/RLUo7 on line 14 and defined in /in/RLUo7:9
Stack trace:
#0 /in/RLUo7(14): foo(NULL)
#1 {main}
  thrown in /in/RLUo7 on line 9

Process exited with code 255.