Macros starting with `r' in sys

• RB_CONTIGGET sys/tty.h:79
• RB_CONTIGPUT sys/tty.h:74
• RB_LEN sys/tty.h:70
• RB_PRED sys/tty.h:67
• RB_ROLLOVER sys/tty.h:64
• RB_SUCC sys/tty.h:61
• remque sys/systm.h:80
• ROUNDDOWN sys/gprof.h:113
• roundup sys/param.h:174