Description:
------------
When preg_matching a multiline string containing '<?', dumping the resulting $matches array hangs the script engine.

I've noticed the same in php 4.4.1 and 5.2.1.

Reproduce code:
---------------
<?php
echo '<pre>';
$var = "<? // <- Remove first two chars and this script won't hang.";
$pattern = "/^(.+)$/s";
preg_match($pattern, $var, $matches);
print_r($matches);
exit;


Expected result:
----------------
Array
(
    [0] =>  <? // <- Remove first two chars and this script won't hang.
    [1] =>  <? // <- Remove first two chars and this script won't hang.
)

Actual result:
--------------
Array
(