- Add more testcases.
- Fix trivial compile failure
- Remove handling of "column IN (one_element)". This is converted to equality 
  elsewhere

mysql-test/r/table_elim.result:
  MWL#17: Table elimination
  - Add more testcases.
  - Fix trivial compile failure
mysql-test/t/table_elim.test:
  MWL#17: Table elimination
  - Add more testcases
sql/mysqld.cc:
  MWL#17: Table elimination
  - Fix trivial compile failure
sql/opt_table_elimination.cc:
  MWL#17: Table elimination
  - Add more testcases.
  - Remove handling of "column IN (one_element)".This is converted to equality 
    elsewhere