Not implement os::unix::fs::chroot for vxworks

Author: CDirkx

std/src/os/unix/fs.rs

@@ -906,7 +906,7 @@ impl DirBuilderExt for fs::DirBuilder {
 /// }
 /// ```
 #[unstable(feature = "unix_chroot", issue = "84715")]
-#[cfg(not(target_os = "fuchsia"))]
+#[cfg(not(any(target_os = "fuchsia", target_os = "vxworks")))]
 pub fn chroot<P: AsRef<Path>>(dir: P) -> io::Result<()> {
     sys::fs::chroot(dir.as_ref())
 }

std/src/sys/unix/fs.rs

@@ -1329,7 +1329,7 @@ pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
     Ok(bytes_copied as u64)
 }
 
-#[cfg(not(target_os = "fuchsia"))]
+#[cfg(not(any(target_os = "fuchsia", target_os = "vxworks")))]
 pub fn chroot(dir: &Path) -> io::Result<()> {
     let dir = cstr(dir)?;
     cvt(unsafe { libc::chroot(dir.as_ptr()) })?;