rustc: 1.21.0 -> 1.22.1

* removed --enable-clang as it has disappeared
* removed old fixes that have been integrated in upstream

pkgs/development/compilers/rust/default.nix

@@ -6,7 +6,7 @@
 
 let
   rustPlatform = recurseIntoAttrs (makeRustPlatform (callPackage ./bootstrap.nix {}));
-  version = "1.21.0";
+  version = "1.22.1";
 in
 rec {
   rustc = callPackage ./rustc.nix {
@@ -18,7 +18,7 @@ rec {
 
     src = fetchurl {
       url = "https://static.rust-lang.org/dist/rustc-${version}-src.tar.gz";
-      sha256 = "1yj8lnxybjrybp00fqhxw8fpr641dh8wcn9mk44xjnsb4i1c21qp";
+      sha256 = "1lrzzp0nh7s61wgfs2h6ilaqi6iq89f1pd1yaf65l87bssyl4ylb";
     };
 
     patches = [