gnu: Add rust-msvc-demangler-0.9.

* gnu/packages/crates-io.scm (rust-msvc-demangler-0.9): Add variable.

Change-Id: I2c38ef083f08628e94679f4f0bee8d73629974c2
Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/crates-io.scm

@@ -40601,6 +40601,27 @@ debug_assert_* macros.")
     (description "Linux kernel MPTCP path manager netlink Library.")
     (license license:expat)))
 
+(define-public rust-msvc-demangler-0.9
+  (package
+    (name "rust-msvc-demangler")
+    (version "0.9.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "msvc-demangler" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32 "1j7kkmbd9yvhk7dmvd29pqcg9mcjdw5p1ia1kihh16zss1nprdmz"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:cargo-inputs (("rust-bitflags" ,rust-bitflags-1))))
+    (home-page "https://github.com/mstange/msvc-demangler-rust")
+    (synopsis "Rust library that demangles C++ symbols mangled by MSVC")
+    (description
+     "This package provides a rust library that demangles (undecorates)
+C++ symbols mangled by MSVC.")
+    (license (list license:expat license:ncsa))))
+
 (define-public rust-multer-2
   (package
     (name "rust-multer")