mysql-test/r/alter_table.result:
  Updated results after merge
mysql-test/r/drop_temp_table.result:
  Updated results after merge
mysql-test/r/union.result:
  Updated results after merge
sql/sql_db.cc:
  optimization: Use my_stat() instead of my_dir() to test if directory exists
sql/sql_union.cc:
  Fixed error in merge