Description:
------------
If ATTR_PERSISTENT is set to true and running a php-script using the CLI.
The script segmentation faults at the end of execution (not during)


Reproduce code:
---------------
<?php
$pdo = new PDO('mysql:host=xxxx;dbname=yyyy', 'wwww', 'pppp',
                    array(PDO::ATTR_PERSISTENT => true));
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$x = $pdo->prepare('SELECT 1');
$x->execute();
$row = $x->fetch();

var_dump($row);
?>

Expected result:
----------------
No segmentation faults.

Actual result:
--------------
Script runs fine, but segmentation faults after execution.