[Libguestfs] [PATCH nbdkit 0/3] ocaml: Fix handling of parameter types

I've already pushed this, it's FYI only. This is really a follow up to Laszlo Ersek's fixes to the OCaml bindings in libnbd (https://listman.redhat.com/archives/libguestfs/2022-January/msg00093.html) Firstly there's a huge mistake: We were using caml_copy_int32 to construct int64 offsets -- Ooops. This actually works (to some extent) on little endian platforms. The second and third patches deal with count parameters, and therefore possibly overlap with Eric Blake's work. The list of extents was already being passed using int64. Rich.