Description:
------------
Cant get element by key after transform object to array

Test script:
---------------
$a = [0 => 1, 1=>3, 2=> 6];
print_r($a);
$o  = new stdClass();
foreach($a as $key => $value){
	$o->$key = $value;
}

$a = (array)$o;
print_r($a);
foreach ($a as $key => $id) {
                unset($a[$key]);
	
        }

print_r($a);

Expected result:
----------------
Array ( [0] => 1 [1] => 3 [2] => 6 ) Array ( [0] => 1 [1] => 3 [2] => 6 ) Array()

Actual result:
--------------
Array ( [0] => 1 [1] => 3 [2] => 6 ) Array ( [0] => 1 [1] => 3 [2] => 6 ) Array ( [0] => 1 [1] => 3 [2] => 6 )