Description:
------------
The following code causes a segfault on 64-bit systems, but not on 32-bit systems.

Setting a non-array value, or removing the duplicate "test" key in the $cache->get() call, fixes the problem.

Probably related to bug #12624

Reproduce code:
---------------
$cache = new Memcache;

$cache->connect("localhost", 11211);

$cache->set("test", array("test"));

var_dump($cache->get(array(
        "test",
        "test",
)));