Description:
------------
Running on the latest of everything, the attached reduced test case fails when opcache is enabled.

"Warning: Narrowing occurred during type inference. Please file a bug report on bugs.php.net in Unknown on line 0"

It is affecting Composr CMS, we found it from in the wild for customer(s) upgraded to PHP 7.2.

This is not fixed by these commits:
https://github.com/php/php-src/commit/776bef8447f2848c043e4716a1e08c4ac5a88fdb
https://github.com/php/php-src/commit/5934bff91337b876195e9290b0811240052be7a3
I also confirmed it is not fixed in git HEAD.

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

function foobar()
{
    do {
        foreach ($a as $i => $_) {
            $a[$i][0] += 1;
        }

        $a[] = array(0, 0);
    } while ($x !== false);
}