The crash happens because second filling of the same I_S table happens in
case of subselect with order by. table->sort.io_cache previously allocated
in create_sort_index() is deleted during second filling
(function get_schema_tables_result). There are two places where
I_S table can be filled: JOIN::exec and create_sort_index().
To fix the bug we should check if the table was already filled
in one of these places and skip processing of the table in second.


mysql-test/r/information_schema.result:
  test case
mysql-test/t/information_schema.test:
  test case
sql/mysql_priv.h:
  added new parameter 'executed_place' to function get_schema_tables_result()
sql/sql_select.cc:
  added new parameter 'executed_place' to function get_schema_tables_result()
sql/sql_show.cc:
  added more accurate check for cases when we need to refresh I_S table
sql/table.cc:
  added more accurate check for cases when we need to refresh I_S table
sql/table.h:
  added more accurate check for cases when we need to refresh I_S table