Description:
------------
array_flip() converts some string values to integers (but some not) in non-associative array and assigns strange values, not value appropriate to last occurence.

Reproduce code:
---------------
---
From manual page: http://www.php.net/function.array-flip#Description
---
<?php
    $foo = array(
        '1',
        '1',
        '2&#836;',
        '2',
        '2',
        '2',
        '3',
    );
    
    var_dump(array_flip($foo));

Expected result:
----------------
array(3) {
  ["1"]=>
  int(1)
  ["2&#836;"]=>
  int(5)
  ["3"]=>
  int(6)
}


Actual result:
--------------
array(4) {
  [1]=>
  int(1)
  ["2&#836;"]=>
  int(2)
  [2]=>
  int(5)
  [3]=>
  int(6)
}