mysql-test/include/ps_modify.inc:
  replace ... select now works.
mysql-test/r/ps_2myisam.result:
  replace ... select now works.
mysql-test/r/ps_3innodb.result:
  replace ... select now works.
mysql-test/r/ps_4heap.result:
  replace ... select now works.
mysql-test/r/ps_5merge.result:
  replace ... select now works.
mysql-test/r/ps_6bdb.result:
  replace ... select now works.
mysql-test/r/ps_7ndb.result:
  replace ... select now works.
mysql-test/t/ps_7ndb.test:
  replace ... select now works.
sql/sql_prepare.cc:
  Enable SQLCOM_REPLACE_SELECT: no need for any code changes but
  enable this SQLCOM in the switch.