gnu: Add rust-windows-x86-64-gnullvm-0.42.

* gnu/packages/crates-io.scm (rust-windows-x86-64-gnullvm-0.42):
New variable.

Signed-off-by: Tobias Geerinckx-Rice <me@tobias.gr>

gnu/packages/crates-io.scm

@@ -68223,6 +68223,25 @@ windows crate.")
                (base32
                 "0m79bhdr54g4h4wh2q8wkjlkypb5wvl7xzhc2csiaqb5yl4z8cdw"))))))
 
+(define-public rust-windows-x86-64-gnullvm-0.42
+  (package
+    (name "rust-windows-x86-64-gnullvm")
+    (version "0.42.0")
+    (source (origin
+              (method url-fetch)
+              (uri (crate-uri "windows-x86-64-gnullvm" version))
+              (file-name (string-append name "-" version ".tar.gz"))
+              (sha256
+               (base32
+                "0a10rns9b07m9snlr97iqxq42zi9ai547gb5fqlv7vihpb92bm89"))))
+    (build-system cargo-build-system)
+    (arguments (list #:skip-build? #t))
+    (home-page "https://github.com/microsoft/windows-rs")
+    (synopsis "Code gen support for the windows crate")
+    (description
+     "This package provides code gen support for the windows crate.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-xmltree-0.10
   (package
     (name "rust-xmltree")