Fix Windows compilation errors.

Author: sunfishcode

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

@@ -7,6 +7,7 @@ use crate::convert::TryFrom;
 use crate::ffi::c_void;
 use crate::fmt;
 use crate::fs;
+use crate::io;
 use crate::marker::PhantomData;
 use crate::mem::forget;
 use crate::ptr::NonNull;
@@ -114,7 +115,7 @@ impl BorrowedHandle<'_> {
 impl OwnedHandle {
     /// Creates a new `OwnedHandle` instance that shares the same underlying file handle
     /// as the existing `OwnedHandle` instance.
-    pub fn try_clone(&self) -> crate::io::Result<FileDesc> {
+    pub fn try_clone(&self) -> crate::io::Result<Self> {
         let handle = self.duplicate(0, false, c::DUPLICATE_SAME_ACCESS)?;
 
         Ok(unsafe { OwnedHandle::from_raw_handle(handle) })

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

@@ -4,7 +4,9 @@
 
 use super::raw::{AsRawSocket, FromRawSocket, IntoRawSocket, RawSocket};
 use crate::fmt;
+use crate::io;
 use crate::marker::PhantomData;
+use crate::mem;
 use crate::mem::forget;
 use crate::sys::c;
 use crate::sys::cvt;
@@ -91,7 +93,7 @@ impl OwnedSocket {
         };
 
         if socket != c::INVALID_SOCKET {
-            unsafe { Ok(Self::from_inner(OwnedSocket::from_raw_socket(socket))) }
+            unsafe { Ok(Self(OwnedSocket::from_raw_socket(socket))) }
         } else {
             let error = unsafe { c::WSAGetLastError() };
 
@@ -115,14 +117,19 @@ impl OwnedSocket {
             }
 
             unsafe {
-                let socket = Self::from_inner(OwnedSocket::from_raw_socket(socket));
+                let socket = Self(OwnedSocket::from_raw_socket(socket));
                 socket.set_no_inherit()?;
                 Ok(socket)
             }
         }
     }
 }
 
+/// Returns the last error from the Windows socket interface.
+fn last_error() -> io::Error {
+    io::Error::from_raw_os_error(unsafe { c::WSAGetLastError() })
+}
+
 impl AsRawSocket for BorrowedSocket<'_> {
     #[inline]
     fn as_raw_socket(&self) -> RawSocket {

library/std/src/sys/windows/fs.rs

@@ -455,7 +455,7 @@ impl File {
     }
 
     pub fn duplicate(&self) -> io::Result<File> {
-        Ok(Self(self.0.try_clone()?))
+        Ok(Self { handle: self.handle.try_clone()? })
     }
 
     fn reparse_point<'a>(

library/std/src/sys/windows/net.rs

@@ -208,7 +208,7 @@ impl Socket {
     }
 
     pub fn duplicate(&self) -> io::Result<Socket> {
-        Ok(Self(self.0.duplicate()?))
+        Ok(Self(self.0.try_clone()?))
     }
 
     fn recv_with_flags(&self, buf: &mut [u8], flags: c_int) -> io::Result<usize> {