Macros starting with `f' in bsd/sys

• FD_CLR bsd/sys/types.h:158
• FD_COPY bsd/sys/types.h:160
• fdfile bsd/sys/filedesc.h:115
• fdflags bsd/sys/filedesc.h:117
• FD_ISSET bsd/sys/types.h:159
• FD_SET bsd/sys/types.h:157
• FD_ZERO bsd/sys/types.h:161
• FFLAGS bsd/sys/fcntl.h:126
• FREE bsd/sys/malloc.h:263
• FREE_ZONE bsd/sys/malloc.h:269