Macros starting with `b' in sys

• B_ADAPTOR sys/reboot.h:67
• B_CONTROLLER sys/reboot.h:70
• B_PARTITION sys/reboot.h:76
• btokmemx sys/malloc.h:262
• btokup sys/malloc.h:263
• B_TYPE sys/reboot.h:79
• BUCKETINDX sys/malloc.h:225
• B_UNIT sys/reboot.h:73