[PATCH v2 0/4] MR6045: server: Reimplement mailslots using server-side I/O.

[Elizabeth Figura (＠zfigura)]

This fixes various corner cases.

This is not motivated by any particular application. However, the server-side
code seems at least as simple as the existing client-side code, is more
accurate, and removes a potential source of complication from any future work
involving asyncs.

--
  v2: server: Reimplement mailslots using server-side I/O.
      server: Treat completion with error before async_handoff() as error.
      kernel32/tests: Add more mailslot tests.
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/6045