Add I/O safety details

Co-authored-by: Josh Triplett <josh@joshtriplett.org>

Author: Mark-Simulacrum

posts/2022-08-11-Rust-1.63.0.md

@@ -32,12 +32,12 @@ Please [report] any bugs you might come across!
 
 Previously, Rust code working with platform APIs taking raw file descriptors (on
 unix-style platforms) or handles (on Windows) would typically work directly with
-a platform-specific representation of the descriptor (for example, a `c_int`).
+a platform-specific representation of the descriptor (for example, a `c_int`, or the alias `RawFd`).
 For Rust bindings to such native APIs, the type system then failed to encode
 whether the API would take ownership of the file descriptor (e.g., `close`) or
 merely borrow it (e.g., `dup`).
 
-Now, Rust provides wrapper types such as [`BorrowedFd`], which are marked as
+Now, Rust provides wrapper types such as [`BorrowedFd`] and [`OwnedFd`], which are marked as
 `#[repr(transparent)]`, meaning that `extern "C"` bindings can directly take
 these types to encode the ownership semantics. See the stabilized APIs section
 for the full list of wrapper types stabilized in 1.63, currently, they are
@@ -48,6 +48,7 @@ We recommend that new APIs use these types instead of the previous type aliases
 
 [`RawFd`]: https://doc.rust-lang.org/stable/std/os/unix/io/type.RawFd.html
 [`BorrowedFd`]: https://doc.rust-lang.org/stable/std/os/unix/io/struct.BorrowedFd.html
+[`OwnedFd`]: https://doc.rust-lang.org/stable/std/os/unix/io/struct.OwnedFd.html
 
 ### Turbofish for generics in functions with `impl Trait`