Description:
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When I try to compare a PDO object with itself, it's supposed to be equal, but the '==' operator doesn't seems to work properly.

Reproduce code:
---------------
<?
$oPDO = new PDO('sqlite::memory:');
var_dump($oPDO == $oPDO);
?>


Expected result:
----------------
bool(true)

Actual result:
--------------
bool(false)