Implement raw_window_handle::HasRawWindowHandle for Window type (#1105)

* Implement raw_window_handle::HasRawWindowHandle for Window type

* Format

* Address compilation issues

* Fix Linux build hopefully

* Fix iOS build

src/platform_impl/linux/x11/window.rs

@@ -1,3 +1,4 @@
+use raw_window_handle::unix::X11Handle;
 use std::{
     cmp,
     collections::HashSet,
@@ -1375,4 +1376,13 @@ impl UnownedWindow {
             .unwrap()
             .insert(WindowId(self.xwindow));
     }
+
+    #[inline]
+    pub fn raw_window_handle(&self) -> X11Handle {
+        X11Handle {
+            window: self.xwindow,
+            display: self.xconn.display as _,
+            ..X11Handle::empty()
+        }
+    }
 }