Minimum 64-bit support

The minimum needed by a PFS to be 64-bit supporting is:

If the only data moves to or from the user address space are done with osi_uiomove, the PFS just needs to set pfsi_addr64 during initialization.
If osi_copyin or osi_copyout are used for user buffers, the PFS must check the FuioAddr64 flag at each of these calls, and use osi_copy64 or osi_uiomove whenever this flag is on.
If the PFS does its own MVCSKs and MVCDKs, it must check the FuioAddr64 flag at each of these locations and handle moves with 64-bit addresses; or call osi_copy64 or osi_uiomove at these points. Doing your own moves is, of course, fastest.