windows: Add support for SSH (#29145)

Closes #19892

This PR builds on top of #20587 and improves upon it.

Release Notes:

- N/A

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>

crates/net/src/async_net.rs

@@ -0,0 +1,69 @@
+#[cfg(not(target_os = "windows"))]
+pub use smol::net::unix::{UnixListener, UnixStream};
+
+#[cfg(target_os = "windows")]
+pub use windows::{UnixListener, UnixStream};
+
+#[cfg(target_os = "windows")]
+pub mod windows {
+    use std::{
+        io::Result,
+        path::Path,
+        pin::Pin,
+        task::{Context, Poll},
+    };
+
+    use smol::{
+        Async,
+        io::{AsyncRead, AsyncWrite},
+    };
+
+    pub struct UnixListener(Async<crate::UnixListener>);
+
+    impl UnixListener {
+        pub fn bind<P: AsRef<Path>>(path: P) -> Result<Self> {
+            Ok(UnixListener(Async::new(crate::UnixListener::bind(path)?)?))
+        }
+
+        pub async fn accept(&self) -> Result<(UnixStream, ())> {
+            let (sock, _) = self.0.read_with(|listener| listener.accept()).await?;
+            Ok((UnixStream(Async::new(sock)?), ()))
+        }
+    }
+
+    pub struct UnixStream(Async<crate::UnixStream>);
+
+    impl UnixStream {
+        pub async fn connect<P: AsRef<Path>>(path: P) -> Result<Self> {
+            Ok(UnixStream(Async::new(crate::UnixStream::connect(path)?)?))
+        }
+    }
+
+    impl AsyncRead for UnixStream {
+        fn poll_read(
+            mut self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &mut [u8],
+        ) -> Poll<Result<usize>> {
+            Pin::new(&mut self.0).poll_read(cx, buf)
+        }
+    }
+
+    impl AsyncWrite for UnixStream {
+        fn poll_write(
+            mut self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &[u8],
+        ) -> Poll<Result<usize>> {
+            Pin::new(&mut self.0).poll_write(cx, buf)
+        }
+
+        fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+            Pin::new(&mut self.0).poll_flush(cx)
+        }
+
+        fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<()>> {
+            Pin::new(&mut self.0).poll_close(cx)
+        }
+    }
+}