Some improvement in Item_int_with_ref class comment.

  void print(String *str);

};

/*

  The following class is used to optimize comparing of date and bigint columns

  We need to save the original item, to be able to set the field to the

  original value in 'opt_range'.

  An instance of Item_int_with_ref may refer to a signed or an unsigned

  integer.

  We need to save the original item ('ref') to be able to call

  ref->save_in_field(). This is used to create index search keys.

  An instance of Item_int_with_ref may have signed or unsigned integer value.

*/

class Item_int_with_ref :public Item_int