refernces if subqueri is not in HAVING clause (BUG#7079)
  and the same used for subquery transformetion


mysql-test/r/subselect.result:
  reference on changable fields from subquery
mysql-test/t/subselect.test:
  reference on changable fields from subquery
sql/item.cc:
  new reference which refer to current value not to result used
sql/item.h:
  new reference which refer to current value not to result used
sql/item_subselect.cc:
  new reference which refer to current value not to result used