online alter and changed field/index options

In handler::check_if_supported_inplace_alter() the server uses a bitmap of flags to tell the engine was this ALTER TABLE is supposed to do.

When only table options are changed, it uses the flag CHANGE_CREATE_OPTION. But when only field or index options are changed, this is not detected, there is no special flag for this situation (and CHANGE_CREATE_OPTION is not used either).