Description:
------------
Cannot use Mysqli functions, without using references.

Reproduce code:
---------------
This code:
$db = mysqli_connect('localhost','Matteo','teo28273');
and this doesn't works:
$db = new mysqli('localhost','Matteo','teo28273');

This code:
$db =& mysqli_connect('localhost','Matteo','teo28273');
and this code works:
$db =& new mysqli('localhost','Matteo','teo28273');



Expected result:
----------------
The following code (and all mysqli functions) work properly:

$db = mysqli_connect('localhost','Matteo','teo28273'); or
$db = new mysqli('localhost','Matteo','teo28273');



Actual result:
--------------
Produces this error:
#Fatal error: Trying to clone an uncloneable object of class mysqli in [***]\index.php on line 4