gnu: Add rust-cxx-1.

* gnu/packages/crates-io.scm (rust-cxx-1): New variable.
(rust-cxx-0.5): Inherit from rust-cxx-1.

gnu/packages/crates-io.scm

@@ -11006,8 +11006,42 @@ ristretto255 and Curve25519")
 attributes.")
     (license (list license:asl2.0 license:expat))))
 
+(define-public rust-cxx-1
+  (package
+    (name "rust-cxx")
+    (version "1.0.49")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "cxx" version))
+        (file-name
+         (string-append name "-" version ".tar.gz"))
+        (sha256
+         (base32
+          "0xj29zzd45bkk797902h22kppzmrzm7v9a2wijfiqr964vhrldk5"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:tests? #f  ; Cannot compile cxx-test-suite.
+       #:rust ,rust-1.48    ; or newer
+       #:cargo-inputs
+       (("rust-cc" ,rust-cc-1)
+        ("rust-cxxbridge-flags" ,rust-cxxbridge-flags-1)
+        ("rust-cxxbridge-macro" ,rust-cxxbridge-macro-1)
+        ("rust-link-cplusplus" ,rust-link-cplusplus-1))
+       #:cargo-development-inputs
+       (("rust-cxx-build" ,rust-cxx-build-1)
+        ("rust-cxx-gen" ,rust-cxx-gen-0.7)
+        ("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-0.5
   (package
+    (inherit rust-cxx-1)
     (name "rust-cxx")
     (version "0.5.10")
     (source
@@ -11019,7 +11053,6 @@ attributes.")
         (sha256
          (base32
           "1alj19zf8jm5j8c8hynqb36f0vyjqs8yhwmxpcapfmb5lav4ipgb"))))
-    (build-system cargo-build-system)
     (arguments
      `(#:tests? #f  ; Cannot compile cxx-test-suite.
        #:cargo-inputs
@@ -11032,7 +11065,7 @@ attributes.")
         ("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))))
+        ("rust-trybuild" ,rust-trybuild-1))))))
 
 (define-public rust-cxx-build-1
   (package