darwin packages: Get ready for cross

If things build fine with `stdenvNoCC`, let them use that. If tools
might be prefixed, prepare for that, either by directly splicing or just
using the env vars provided by the wrapper setup-hooks.

Co-authored-by: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>

pkgs/os-specific/darwin/darwin-stubs/default.nix

@@ -1,6 +1,6 @@
-{ stdenv, fetchurl }:
+{ stdenvNoCC, fetchurl }:
 
-stdenv.mkDerivation {
+stdenvNoCC.mkDerivation {
   pname = "darwin-stubs";
   version = "10.12";