Description:
------------
This is not a bug report like #38337.

Shouldn't the return type of explode be restricted to an array given valid inputs (strings)?
This would mean that if an empty string was passed as the delimiter, the return would be an array containing individual characters.

I doubt this would break any existing code unless people used explode to check that the delimiter === ''

Reproduce code:
---------------
<?php
$x = explode('', 'abc');
?>

Expected result:
----------------
$x = array('a','b','c')

Actual result:
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$x = false