Fix for another optimize bug is undone, as the new one handles both cases.
test added


mysql-test/r/myisam.result:
  updated
mysql-test/t/myisam.test:
  optimize table corruption test
sql/ha_myisam.cc:
  optimize table corruption fixed, though more clean fix is desired.
  Fix for another optimize bug is undone, as the new one handles both cases.