unistd::initgroups: Add todo note about FreeBSD support

Author: JayH5

src/unistd.rs

@@ -1002,6 +1002,7 @@ pub fn setgroups(groups: &[Gid]) -> Result<()> {
 /// of. The additional group `group` is also added to the list.
 ///
 /// [Further reading](http://man7.org/linux/man-pages/man3/initgroups.3.html)
+// TODO: Get initgroups binding added for FreeBSD in libc
 #[cfg(any(target_os = "android", target_os = "ios", target_os = "linux", target_os = "macos"))]
 pub fn initgroups(user: &CString, group: Gid) -> Result<()> {
     cfg_if! {