functions".

We should ignore alias when we check if table was already marked as temporary
when we calculate set of tables to be prelocked. Otherwise we will erroneously
treat tables which are used in same routine and have same name but different
alias as non-temporary.


mysql-test/r/sp.result:
  Added test for bug #12198 "Temporary table aliasing does not work inside stored
  functions" and other tests which cover handling of temporary tables in prelocked
  mode.
mysql-test/t/sp.test:
  Added test for bug #12198 "Temporary table aliasing does not work inside stored
  functions" and other tests which cover handling of temporary tables in prelocked
  mode.
sql/sp_head.cc:
  sp_head::merge_table_list():
    We should ignore alias when we check if table was already marked as temporary
    when we calculate set of tables to be prelocked. Otherwise we will erroneously
    treat tables which are used in same routine and have same name but different
    alias as non-temporary.