[MLton] Phantom typing of sockets broken in MLton

[Vesa Karvonen]

Just a quick note before going to bed.  Phantom typing of sockets
seems broken in MLton.  Here is a small example that should not pass
type checking (but does in MLton):

val socket = INetSock.TCP.socket ()
val () = Socket.listen (socket, 1)
val _ = Socket.recvVec (socket, 1)

Both SML/NJ and Poly/ML reject this example.

-Vesa Karvonen