treewide: Get rid of all uses of crossConfig

The hack of using `crossConfig` to enforce stricter handling of
dependencies is replaced with a dedicated `strictDeps` for that purpose.
(Experience has shown that my punning was a terrible idea that made more
difficult and embarrising to teach teach.)

Now that is is clear, a few packages now use `strictDeps`, to fix
various bugs:

 - bintools-wrapper and cc-wrapper

pkgs/build-support/cc-wrapper/default.nix

@@ -201,6 +201,7 @@ stdenv.mkDerivation {
       ln -s $ccPath/${targetPrefix}ghdl $out/bin/${targetPrefix}ghdl
     '';
 
+  strictDeps = true;
   propagatedBuildInputs = [ bintools ];
   depsTargetTargetPropagated = extraPackages;
 

pkgs/build-support/cc-wrapper/setup-hook.sh

@@ -60,7 +60,7 @@ set -u
 # native compile.
 #
 # TODO(@Ericson2314): No native exception
-[[ -z ${crossConfig-} ]] || (( "$hostOffset" < 0 )) || return 0
+[[ -z ${strictDeps-} ]] || (( "$hostOffset" < 0 )) || return 0
 
 # It's fine that any other cc-wrapper will redefine this. Bash functions close
 # over no state, and there's no @-substitutions within, so any redefined