Fix build on OpenBSD caused by missing lutimes

lutimes doesn't exist on OpenBSD so it needs to be under conditional
compilation.

The only "reference" that I could find related to this is the discussion
here: rust-lang/libc#790

Author: thendiscard

src/sys/stat.rs

@@ -209,7 +209,8 @@ pub fn utimes<P: ?Sized + NixPath>(path: &P, atime: &TimeVal, mtime: &TimeVal) -
 /// # References
 ///
 /// [lutimes(2)](http://pubs.opengroup.org/onlinepubs/9699919799/functions/lutimes.html).
-#[cfg(not(target_os = "android"))]
+#[cfg(not(any(target_os = "android",
+              target_os = "openbsd")))]
 pub fn lutimes<P: ?Sized + NixPath>(path: &P, atime: &TimeVal, mtime: &TimeVal) -> Result<()> {
     let times: [libc::timeval; 2] = [*atime.as_ref(), *mtime.as_ref()];
     let res = path.with_nix_path(|cstr| unsafe {

test/test_stat.rs

@@ -7,7 +7,10 @@ use std::time::{Duration, UNIX_EPOCH};
 use libc::{S_IFMT, S_IFLNK};
 
 use nix::fcntl;
+#[cfg(not(any(target_os = "openbsd")))]
 use nix::sys::stat::{self, fchmod, fchmodat, futimens, lutimes, stat, utimes, utimensat};
+#[cfg(any(target_os = "openbsd"))]
+use nix::sys::stat::{self, fchmod, fchmodat, futimens, stat, utimes, utimensat};
 use nix::sys::stat::{Mode, FchmodatFlags, UtimensatFlags};
 
 #[cfg(not(any(target_os = "netbsd")))]
@@ -196,6 +199,7 @@ fn test_utimes() {
 }
 
 #[test]
+#[cfg(not(any(target_os = "openbsd")))]
 fn test_lutimes() {
     let tempdir = tempfile::tempdir().unwrap();
     let target = tempdir.path().join("target");