stdenv-setup and misc pkgs: Revert to space-deliminated propagated-* files

We cannot switch to line-delimited yet, because certain Nix commands do
not read in the entire file, but just the first line.

pkgs/misc/misc.nix

@@ -23,7 +23,7 @@ in
   */
   collection = {list, name} : runCommand "collection-${name}" {} ''
     mkdir -p $out/nix-support
-    printLines ${builtins.toString list} > $out/nix-support/propagated-user-env-packages
+    printWords ${builtins.toString list} > $out/nix-support/propagated-user-env-packages
   '';
 
   /* creates a derivation symlinking references C/C++ libs into one include and lib directory called $out/cdt-envs/${name}