unix: add mlock/munlock/mlockall/munlockall/mprotect to *BSD

Change-Id: I01c5dd902bbc349b860600ec2b3d556e2dc406c9
Reviewed-on: https://go-review.googlesource.com/1921
Reviewed-by: Ian Lance Taylor <iant@golang.org>

unix/syscall_openbsd.go

@@ -165,6 +165,11 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 //sys	Mkdir(path string, mode uint32) (err error)
 //sys	Mkfifo(path string, mode uint32) (err error)
 //sys	Mknod(path string, mode uint32, dev int) (err error)
+//sys	Mlock(b []byte) (err error)
+//sys	Mlockall(flags int) (err error)
+//sys	Mprotect(b []byte, prot int) (err error)
+//sys	Munlock(b []byte) (err error)
+//sys	Munlockall() (err error)
 //sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
 //sys	Open(path string, mode int, perm uint32) (fd int, err error)
 //sys	Pathconf(path string, name int) (val int, err error)
@@ -249,16 +254,12 @@ func Getfsstat(buf []Statfs_t, flags int) (n int, err error) {
 // mkdirat
 // mkfifoat
 // mknodat
-// mlock
-// mlockall
 // mount
 // mquery
 // msgctl
 // msgget
 // msgrcv
 // msgsnd
-// munlock
-// munlockall
 // nfssvc
 // nnpfspioctl
 // openat