gnu: Add rust-asn1-0.20.

* gnu/packages/crates-tls.scm (rust-asn1-0.20): New variable.
(rust-asn1-0.15): Inherit from rust-asn1-0.20.

Change-Id: I28c12d4e910d40970d40bcf443a018cbdea3c812

gnu/packages/crates-tls.scm

@@ -46,8 +46,31 @@
   #:use-module (gnu packages tls)
   #:use-module (gnu packages valgrind))
 
+(define-public rust-asn1-0.20
+  (package
+    (name "rust-asn1")
+    (version "0.20.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "asn1" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32 "0ckg83ingvagwjvmxadjjmkgna5kvlvrfx9arlfvzqhxxas892rd"))))
+    (build-system cargo-build-system)
+    (arguments
+     `(#:cargo-inputs (("rust-asn1-derive" ,rust-asn1-derive-0.20)
+                       ("rust-itoa" ,rust-itoa-1))
+       #:cargo-development-inputs (("rust-libc" ,rust-libc-0.2))))
+    (home-page "https://github.com/alex/rust-asn1")
+    (synopsis "ASN.1 (DER) parser and writer for Rust")
+    (description
+     "This is a Rust library for parsing and generating ASN.1 data (DER only).")
+    (license license:bsd-3)))
+
 (define-public rust-asn1-0.15
   (package
+    (inherit rust-asn1-0.20)
     (name "rust-asn1")
     (version "0.15.5")
     (source
@@ -57,17 +80,10 @@
        (file-name (string-append name "-" version ".tar.gz"))
        (sha256
         (base32 "1nzg1gjiyfvpvrf3i7i8j21165snf5livqg6x2sjf9m2i77cngmf"))))
-    (build-system cargo-build-system)
     (arguments
      `(#:cargo-inputs
        (("rust-asn1-derive" ,rust-asn1-derive-0.15))
-       #:cargo-development-inputs
+       #:cargo-development-inputs (("rust-libc" ,rust-libc-0.2))))))
-       (("rust-libc" ,rust-libc-0.2))))
-    (home-page "https://github.com/alex/rust-asn1")
-    (synopsis "ASN.1 (DER) parser and writer")
-    (description
-     "This is a Rust library for parsing and generating ASN.1 data (DER only).")
-    (license license:bsd-3)))
 
 (define-public rust-asn1-0.13
   (package