Defines starting with `u' in sys

• u_ar0 sys/user.h:84
• u_code sys/user.h:89
• _UCRED_H_ sys/ucred.h:37
• u_dsize sys/user.h:86
• UF_EXCLOSE sys/filedesc.h:82
• UF_MAPPED sys/filedesc.h:83
• _UIO_H_ sys/uio.h:37
• UIO_MAXIOV sys/uio.h:68
• UIO_SMALLIOV sys/uio.h:69
• u_sig sys/user.h:88
• u_ssize sys/user.h:87
• u_tsize sys/user.h:85