unix: implement getrtable/setrtable syscalls on OpenBSD

Change-Id: I9f0ca3c2c1cd79f0c996ebbc7f79a42f740e0d2c
GitHub-Last-Rev: ebd0046a4fefcd70d4b21f043a350c6f4df21cfd
GitHub-Pull-Request: golang/sys#10
Reviewed-on: https://go-review.googlesource.com/107302
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

unix/syscall_openbsd.go

@@ -222,6 +222,7 @@ func Uname(uname *Utsname) error {
 //sysnb	Getppid() (ppid int)
 //sys	Getpriority(which int, who int) (prio int, err error)
 //sysnb	Getrlimit(which int, lim *Rlimit) (err error)
+//sysnb	Getrtable() (rtable int, err error)
 //sysnb	Getrusage(who int, rusage *Rusage) (err error)
 //sysnb	Getsid(pid int) (sid int, err error)
 //sysnb	Gettimeofday(tv *Timeval) (err error)
@@ -259,6 +260,7 @@ func Uname(uname *Utsname) error {
 //sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
 //sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(which int, lim *Rlimit) (err error)
+//sysnb	Setrtable(rtable int) (err error)
 //sysnb	Setsid() (pid int, err error)
 //sysnb	Settimeofday(tp *Timeval) (err error)
 //sysnb	Setuid(uid int) (err error)
@@ -307,7 +309,6 @@ func Uname(uname *Utsname) error {
 // getlogin
 // getresgid
 // getresuid
-// getrtable
 // getthrid
 // ktrace
 // lfs_bmapv
@@ -343,7 +344,6 @@ func Uname(uname *Utsname) error {
 // semop
 // setgroups
 // setitimer
-// setrtable
 // setsockopt
 // shmat
 // shmctl