Description:
------------
PDO::FETCH_FUNC does not work with functions and classes that are inside a namespace.

Reproduce code:
---------------
namespace Foo;

function bar() { var_dump(func_get_args()); }

$pdo  = new ::PDO();
$stmt = $pdo->query('SELECT * FROM foo_bar');
$stmt->fetchAll(PDO::FETCH_FUNC, 'Foo::bar');

Expected result:
----------------
array(2) {
  [0]=>
  string(4) "test"
  [1]=>
  string(4) "data"
}


Actual result:
--------------
Warning: PDOStatement::fetchAll(): SQLSTATE[HY000]: General error: user-supplied class does not exist in /home/operations/Desktop/PHP.php on line 8