Vendor dependencies for 0.3.0 release

vendor/accesskit_windows/src/window_handle.rs

@@ -0,0 +1,32 @@
+// Copyright 2024 The AccessKit Authors. All rights reserved.
+// Licensed under the Apache License, Version 2.0 (found in
+// the LICENSE-APACHE file) or the MIT license (found in
+// the LICENSE-MIT file), at your option.
+
+use windows::Win32::Foundation::HWND;
+
+#[repr(transparent)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct WindowHandle(pub HWND);
+
+unsafe impl Send for WindowHandle {}
+unsafe impl Sync for WindowHandle {}
+
+impl From<HWND> for WindowHandle {
+    fn from(value: HWND) -> Self {
+        Self(value)
+    }
+}
+
+impl From<WindowHandle> for HWND {
+    fn from(value: WindowHandle) -> Self {
+        value.0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    static_assertions::assert_impl_all!(WindowHandle: Send, Sync);
+}