gnu: Add rust-cxx-0.5, rust-cxxbridge-macro-0.5.

* gnu/packages/crates-io.scm (rust-cxx-0.5, rust-cxxbridge-macro-0.5):
New variables.

gnu/packages/crates-io.scm

@@ -6403,6 +6403,38 @@ ristretto255 and Curve25519")
 attributes.")
     (license (list license:asl2.0 license:expat))))
 
+(define-public rust-cxx-0.5
+  (package
+    (name "rust-cxx")
+    (version "0.5.10")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "cxx" version))
+        (file-name
+         (string-append name "-" version ".tar.gz"))
+        (sha256
+         (base32
+          "1alj19zf8jm5j8c8hynqb36f0vyjqs8yhwmxpcapfmb5lav4ipgb"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:tests? #f  ; Cannot compile cxx-test-suite.
+       #:cargo-inputs
+       (("rust-cc" ,rust-cc-1)
+        ("rust-cxxbridge-flags" ,rust-cxxbridge-flags-0.5)
+        ("rust-cxxbridge-macro" ,rust-cxxbridge-macro-0.5)
+        ("rust-link-cplusplus" ,rust-link-cplusplus-1))
+       #:cargo-development-inputs
+       (("rust-cxx-build" ,rust-cxx-build-0.5)
+        ("rust-cxx-gen" ,rust-cxx-gen-0.6)
+        ("rust-cxx-test-suite" ,rust-cxx-test-suite-0.0.0)
+        ("rust-rustversion" ,rust-rustversion-1)
+        ("rust-trybuild" ,rust-trybuild-1))))
+    (home-page "https://cxx.rs")
+    (synopsis "Safe interop between Rust and C++")
+    (description "This package provides a safe interop between Rust and C++.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-cxx-build-0.5
   (package
     (name "rust-cxx-build")
@@ -6504,6 +6536,33 @@ crate into higher level tools.")
 crate (implementation detail).")
     (license (list license:expat license:asl2.0))))
 
+(define-public rust-cxxbridge-macro-0.5
+  (package
+    (name "rust-cxxbridge-macro")
+    (version "0.5.10")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "cxxbridge-macro" version))
+        (file-name
+         (string-append name "-" version ".tar.gz"))
+        (sha256
+         (base32
+          "05mhvchmcb8dpgcqkl5vyxycywp2x42vw1qh2hyxxyi576nmmxsr"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:cargo-inputs
+       (("rust-proc-macro2" ,rust-proc-macro2-1)
+        ("rust-quote" ,rust-quote-1)
+        ("rust-syn" ,rust-syn-1))
+       #:cargo-development-inputs
+       (("rust-cxx" ,rust-cxx-0.5))))
+    (home-page "https://cxx.rs")
+    (synopsis "Implementation detail of the `cxx` crate")
+    (description
+     "This package provides an implementation detail of the @code{cxx} crate.")
+    (license (list license:expat license:asl2.0))))
+
 (define-public rust-darling-0.10
   (package
     (name "rust-darling")