ref: 1442891a3e9f3047b0fda4fed8afc0de5fc7da1a dir: /sys/src/cmd/9l/needed/
> case ASLQ: /* 6 and 57 */ > case ASRAQ: /* sraw Rb,Rs,Ra; srawi sh,Rs,Ra */ /* 6 and 56 */ > case ARLQMI: /* unique, also clear, clearleft clearright*/