unix: add utimensat and use it for UtimesNano on BSD

Follow golang.org/cl/55130 and add the utimensat syscall on *BSD. Use it
in UtimesNano and UtimesNanoAt (which is added on *BSD, akin to the
already existing implementation on Linux and Solaris).

Also add AT_FDCWD and AT_SYMLINK_NOFOLLOW where they are missing. These
might be used with UtimesNanoAt.

In order to be able to generate the syscalls, also add two missing
$GOOS_$GOARCH patterns to mkall.sh. As a side effect, some additional
syscalls are added for openbsd/arm.

Change-Id: I85351098002209f8454ec328cef0cfe9d12c5214
Reviewed-on: https://go-review.googlesource.com/55071
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/unix/zsyscall_openbsd_arm.go b/unix/zsyscall_openbsd_arm.go
index 9cabf57..ca2ed7d 100644
--- a/unix/zsyscall_openbsd_arm.go
+++ b/unix/zsyscall_openbsd_arm.go
@@ -1,5 +1,5 @@
 // mksyscall.pl -l32 -openbsd -arm -tags openbsd,arm syscall_bsd.go syscall_openbsd.go syscall_openbsd_arm.go
-// MACHINE GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
+// Code generated by the command above; see README.md. DO NOT EDIT.
 
 // +build openbsd,arm
 
@@ -10,6 +10,8 @@
 	"unsafe"
 )
 
+var _ syscall.Errno
+
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
 func getgroups(ngid int, gid *_Gid_t) (n int, err error) {
@@ -783,6 +785,74 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Mlock(b []byte) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MLOCK, uintptr(_p0), uintptr(len(b)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mlockall(flags int) (err error) {
+	_, _, e1 := Syscall(SYS_MLOCKALL, uintptr(flags), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Mprotect(b []byte, prot int) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MPROTECT, uintptr(_p0), uintptr(len(b)), uintptr(prot))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Munlock(b []byte) (err error) {
+	var _p0 unsafe.Pointer
+	if len(b) > 0 {
+		_p0 = unsafe.Pointer(&b[0])
+	} else {
+		_p0 = unsafe.Pointer(&_zero)
+	}
+	_, _, e1 := Syscall(SYS_MUNLOCK, uintptr(_p0), uintptr(len(b)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Munlockall() (err error) {
+	_, _, e1 := Syscall(SYS_MUNLOCKALL, 0, 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Nanosleep(time *Timespec, leftover *Timespec) (err error) {
 	_, _, e1 := Syscall(SYS_NANOSLEEP, uintptr(unsafe.Pointer(time)), uintptr(unsafe.Pointer(leftover)), 0)
 	if e1 != 0 {
@@ -1054,6 +1124,26 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Setresgid(rgid int, egid int, sgid int) (err error) {
+	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func Setresuid(ruid int, euid int, suid int) (err error) {
+	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
@@ -1265,3 +1355,18 @@
 	}
 	return
 }
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
+func utimensat(dirfd int, path string, times *[2]Timespec, flags int) (err error) {
+	var _p0 *byte
+	_p0, err = BytePtrFromString(path)
+	if err != nil {
+		return
+	}
+	_, _, e1 := Syscall6(SYS_UTIMENSAT, uintptr(dirfd), uintptr(unsafe.Pointer(_p0)), uintptr(unsafe.Pointer(times)), uintptr(flags), 0, 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}