Description:
------------
When i use preg_replace with the /u utf-8 modifier and an ungreedy search e.g. with *?, the result is different to a call without /u.

Reproduce code:
---------------
<?php
echo "without /u:". preg_replace('/^[^d]*?(d)?$/', '\\1', 'abc');
echo "<br>";
echo "with /u: ".preg_replace('/^[^d]*?(d)?$/u', '\\1', 'abc');
?>

Expected result:
----------------
without /u:
with /u:

Actual result:
--------------
without /u:
with /u: abc