Implemented RDI.  Works for this trivial case: INC	0	1 RDI	0	0 OPR	0	20 OPR	0	21 Clearly needs more testing.
Implemented RDI.  Works for this trivial case:
INC	0	1
RDI	0	0
OPR	0	20
OPR	0	21
Clearly needs more testing.

paulhoadley/PAL