Description:
------------
When I try to use a class which extends PDOStatement, my apache crashes. Here is a simple reproduce script:

Reproduce code:
---------------
class MAppPDOStatement extends PDOStatement {
	function __construct ($pdo) {
		parent::__construct ($pdo);
		$this->setFetchMode (PDO::FETCH_OBJ);
	}
}

$a = new PDO("sqlite::memory:");
$a->exec ("create table test (id int not null unique, name string)");
$a->prepare ("select * from sqlite_master", array (PDO::ATTR_STATEMENT_CLASS => 'MAppPDOStatement'));


Expected result:
----------------
no errors

Actual result:
--------------
Apache crashes.