subprojects: add windows-link and windows-sys

Useful for Kumquat use cases.  Actually, useful for pretty much
anything Windows-related.  This are foundational crates supported
officially by our friends at Microsoft.

Reviewed-by: David Gilhooley <djgilhooley.gmail.com>

subprojects/packagefiles/windows-link-0.2-rs/meson.build

@@ -0,0 +1,20 @@
+# Copyright © 2025 Google
+# SPDX-License-Identifier: MIT
+
+project(
+  'windows-link-rs',
+  'rust',
+  version : '0.2.0',
+  license : 'MIT OR Apache-2.0',
+)
+
+lib = static_library(
+  'windows_link',
+  'src/lib.rs',
+  override_options : ['rust_std=2021', 'build.rust_std=2021'],
+  rust_abi: 'rust',
+)
+
+dep_windows_link = declare_dependency(
+  link_with: [lib],
+)