Description:
------------
$_SESSION variable should be "array" and "super global".
However, within the __destrunct function, $_SESSION changes its value to the reference to the class which implements __destruct function.

[Example]
<?
  session_start();
  $_SESSION["test"] = "test string";

  class test {
      function __destruct()
      {
          // $_SESSION = $this !?
          print_r($_SESSION);
      }
  }

  $test = new test;
?>

[Expected result]
Array ( [test] => test string )

[Actual result]
test Object ( )

Reproduce code:
---------------
<?
  session_start();
  $_SESSION["test"] = "test string";

  class test {
      function __destruct()
      {
          // $_SESSION = $this !?
          print_r($_SESSION);
      }
  }

  $test = new test;
?>

Expected result:
----------------
Array ( [test] => test string )

Actual result:
--------------
test Object ( )