transfer size.
(IMM): New, call IMM_ with the default 32.
(IMMW,IMMB): Likewise, for 16 and 8.
(NIMM, MBIMM): Add size parameter.
(immediate): Likewise. Allow 32768..65535 for 16-bit transfers.
(MOV.W): Use IMMW instead of IMM.
* config/rx-parse.y (ADC,SBB): ADC and SBB only allow .L.
(op_dp20_rm_l): New.
(op_dp20_rim_l): New.
* config/rx-parse.y (op_dp20_rms): Rename to op_dp20_rr, don't allow mem.
(ABS, NEG, NOT): These only take REG or REG,REG (rr, not rms).
* gas/rx/mov.d: Update patterns for fixed MOV.W encoding.