ASM_FMT_B9
op = ASM_OP_BREAK_B, fmt = ASM_FMT_B9;
op = ASM_OP_NOP_B, fmt = ASM_FMT_B9;
op = ASM_OP_HINT_B, fmt = ASM_FMT_B9;
case ASM_FMT_B9: /* 0 dst */