Module Async_kernel__.Job_or_event.Match

Idiomatic usage of Match is:

        let job_or_event = ... in
        let open Job_or_event.Match in
        let K k = kind job_or_event in
        match k, project k job_or_event with
        | Event , event -> ... use event ...
        | Job   , job   -> ... use job ...
type _ kind =
| Event : Async_kernel__.Job_or_event_intf.Event.t kind
| Job : Async_kernel__.Job.t kind
type packed =
| K : _ kind ‑> packed
val kind : t ‑> packed
val project : 'a kind ‑> t ‑> 'a