Description:
------------
It seems there is a conflict when reusing patters while PCRE JIT is enabled, causing a segfault. It's an obscure bug that I couldn't find a solution and had to disable PCRE JIT to get things working.

These are the (strange) requirements to reproduce the segfault:

1) code MUST be namespaced;
2) code must be run on a non debug build;
3) a preg_replace call must happen while iterating over a regex iterator or derivated;
4) both the preg_replace and the regex iterator instance involved must have the exact same regexp patter;

The test script may be easier to understand. Requirement 1 is really a mystery to me :/


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

namespace X;

$iterator =
    new \RegexIterator(
        new \ArrayIterator(['A.phpt', 'B.phpt', 'C.phpt']),
        '/\.phpt$/'
    )
;

foreach ($iterator as $foo) {
    var_dump($foo);
    preg_replace('/\.phpt$/', '', '');
}

echo "Done", PHP_EOL;

?>

Expected result:
----------------
No segfault.

Actual result:
--------------
Segfault.