gnu: Add rust-rustc-hash-1.0.

* gnu/packages/crates-io.scm (rust-rustc-hash-1.0): New variable.

gnu/packages/crates-io.scm

@@ -21803,6 +21803,20 @@ It is automatically published using the compiler repository at
      "This package provides a speedy, non-cryptographic hash used in rustc.")
     (license (list license:asl2.0 license:expat))))
 
+(define-public rust-rustc-hash-1.0
+  (package
+    (inherit rust-rustc-hash-1)
+    (name "rust-rustc-hash")
+    (version "1.0.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (crate-uri "rustc-hash" version))
+       (file-name (string-append name "-" version ".tar.gz"))
+       (sha256
+        (base32
+         "1f4cnbcmz2c3zjidqszc9c4fip37ch4xl74nkkp9dw291j5zqh3m"))))))
+
 (define-public rust-rustc-rayon-0.3
   (package
     (name "rust-rustc-rayon")