Description:
------------
Requesting a string index on a string type using the string as an array always returns first character position in string.

Reproduce code:
---------------
<?php
$input = '386';
echo $input . " / " . $input['tessrthwsrtht'] . "\n";
?>

Expected result:
----------------
PHP should generate an error when this occurs, because this situation occurs when you think a method/function returns a string indexed array but really just returns a string.
In this situation you get some data, but the data is incorrect and this can be very confusing to debug.

Actual result:
--------------
PHP casts the string index to an integer with the value: 0 and returns the first character in the string.