[ucsim-rxk] Fix #3942 Rabbit uCsim MMIDR
regtests: speed up simulation of rabbit ports
[ucsim-r6k] More R6K specific insts
[ucsim-r6k] R6k spec insts on page CB
[ucsim-r6k] Insts on page 49: IO block copy, md5, sha, aes
[ucsim-r6k] Shift/rot reg insts on page 49
[ucsim-r6k] Inc/dec insts on page 49; r6k specific fixes for other inc/dec ops
[ucsim-r6k] R6k spec insts on page 49: ALU with ps and (ps+d) operands