swreg_to_restricted
err = swreg_to_restricted(reg_none(), lreg, rreg, ®, false);
err = swreg_to_restricted(reg_none(), src, reg_imm(bit), ®, false);
err = swreg_to_restricted(dst, lreg, rreg, ®, true);
err = swreg_to_restricted(dst, dst, src, ®, true);
int swreg_to_restricted(swreg dst, swreg lreg, swreg rreg,