treewide: Get rid of libGLU_combined

pkgs/games/prboom/default.nix

@@ -1,8 +1,11 @@
 { stdenv, fetchurl, SDL, SDL_mixer, SDL_net
-, libGLU_combined ? assert false; null
+, libGLU ? null
+, libGL ? null
 , useOpenGL ? stdenv.hostPlatform == stdenv.buildPlatform
 }:
 
+assert useOpenGL -> libGL != null && libGLU != null;
+
 stdenv.mkDerivation rec {
   name = "prboom-2.5.0";
   src = fetchurl {
@@ -11,7 +14,7 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [ SDL SDL_mixer SDL_net ]
-    ++ stdenv.lib.optional useOpenGL libGLU_combined;
+    ++ stdenv.lib.optionals useOpenGL [ libGL libGLU ];
 
   doCheck = stdenv.hostPlatform == stdenv.buildPlatform;