Fix unresolved doc links.

Author: sunfishcode

library/std/src/os/fd/raw.rs

@@ -7,6 +7,10 @@ use crate::io;
 use crate::os::raw;
 #[cfg(unix)]
 use crate::os::unix::io::OwnedFd;
+#[all(cfg(doc), unix)]
+use crate::os::unix::io::{AsFd, FromFd, IntoFd};
+#[all(cfg(doc), target_os = "wasi")]
+use crate::os::unix::io::{AsFd, FromFd, IntoFd};
 #[cfg(target_os = "wasi")]
 use crate::os::wasi::io::OwnedFd;
 use crate::sys_common::{AsInner, IntoInner};

library/std/src/os/windows/io/raw.rs

@@ -5,6 +5,8 @@
 use crate::fs;
 use crate::io;
 use crate::net;
+#[all(cfg(doc), unix)]
+use crate::os::windows::io::{AsHandle, AsSocket, FromHandle, FromSocket, IntoHandle, IntoSocket};
 use crate::os::windows::io::{OwnedHandle, OwnedSocket};
 use crate::os::windows::raw;
 use crate::sys;