Macros starting with `f' in bsd/sys

• FD_CLR bsd/sys/types.h:155
• FD_COPY bsd/sys/types.h:157
• fdfile bsd/sys/filedesc.h:112
• fdflags bsd/sys/filedesc.h:114
• FD_ISSET bsd/sys/types.h:156
• FD_SET bsd/sys/types.h:154
• FD_ZERO bsd/sys/types.h:158
• FFLAGS bsd/sys/fcntl.h:134
• FREE bsd/sys/malloc.h:271
• FREE_ZONE bsd/sys/malloc.h:277
• FSDBG_CODE bsd/sys/kdebug.h:171