function crashes server".

Attempts to execute prepared multi-delete statement which involved trigger or
stored function caused server crashes (the same happened for such statements
included in stored procedures in cases when one tried to execute them more
than once).

The problem was caused by yet another incorrect usage of check_table_access()
routine (the latter assumes that table list which it gets as argument
corresponds to value LEX::query_tables_own_last). We solve this problem by
juggling with LEX::query_tables_own_last value when we call
check_table_access() for LEX::auxilliary_table_list (better solution is too
intrusive and should be done in 5.1).


mysql-test/r/sp-prelocking.result:
  Added test for bug#19634 "Re-execution of multi-delete which involve trigger/
  stored function crashes server".
mysql-test/t/sp-prelocking.test:
  Added test for bug#19634 "Re-execution of multi-delete which involve trigger/
  stored function crashes server".
sql/sql_parse.cc:
  To call safely check_table_access() for LEX::auxilliary_table_list we have
  to juggle with LEX::query_tables_own_last value.