treewide: mark a bunch of failing builds as broken

(cherry picked from commit 23fdbaa37599f490435056b9865023870656571b)
[dezgeg: Un-mark shotcut, tokei & uchiwa that do build on master]

pkgs/development/compilers/rust/beta.nix

@@ -25,6 +25,7 @@ rec {
     ] ++ stdenv.lib.optional stdenv.needsPax ./patches/grsec.patch;
 
     doCheck = false;
+    broken = true;
   };
 
   cargo = callPackage ./cargo.nix rec {

pkgs/development/compilers/rust/nightly.nix

@@ -22,6 +22,7 @@ rec {
     ] ++ stdenv.lib.optional stdenv.needsPax ./patches/grsec.patch;
 
     doCheck = false;
+    broken = true;
   };
 
   cargo = callPackage ./cargo.nix rec {

pkgs/development/compilers/rust/rustc.nix

@@ -10,6 +10,7 @@
 , targetPatches
 , targetToolchains
 , doCheck ? true
+, broken ? false
 , buildPlatform, hostPlatform
 } @ args:
 
@@ -154,5 +155,6 @@ stdenv.mkDerivation {
     maintainers = with maintainers; [ madjar cstrahan wizeman globin havvy wkennington ];
     license = [ licenses.mit licenses.asl20 ];
     platforms = platforms.linux ++ platforms.darwin;
+    broken = broken;
   };
 }