only on some occasions

Referencing an element from the SELECT list in a WHERE 
clause is not permitted. The namespace of the WHERE
clause is the table columns only. This was not enforced
correctly when resolving outer references in sub-queries.

Fixed by not allowing references to aliases in a 
sub-query in WHERE.


mysql-test/include/ps_query.inc:
  Bug #32400: fixed old test queries
mysql-test/r/ps_2myisam.result:
  Bug #32400: fixed old test queries
mysql-test/r/ps_3innodb.result:
  Bug #32400: fixed old test queries
mysql-test/r/ps_4heap.result:
  Bug #32400: fixed old test queries
mysql-test/r/ps_5merge.result:
  Bug #32400: fixed old test queries
mysql-test/r/ps_6bdb.result:
  Bug #32400: fixed old test queries
mysql-test/r/ps_7ndb.result:
  Bug #32400: fixed old test queries
mysql-test/r/subselect.result:
  Bug #32400: test case
mysql-test/t/subselect.test:
  Bug #32400: test case
sql/item.cc:
  Bug #32400: don't allow references to aliases in WHERE
tests/mysql_client_test.c:
  Bug #32400: fixed old test queries