mesa: have all output on /run/opengl-driver{,-32}

Fixes #2242 in a different way (cleaner, I hope).

nixos/modules/hardware/opengl.nix

@@ -93,6 +93,7 @@ in {
               name = "mesa-drivers+txc-${p.mesa_drivers.version}";
               paths = [
                 p.mesa_drivers
+                p.mesa_noglu # mainly for libGL
                 (if cfg.s3tcSupport then p.libtxc_dxtn else p.libtxc_dxtn_s2tc)
               ];
             };

pkgs/development/libraries/mesa/default.nix

@@ -151,11 +151,6 @@ stdenv.mkDerivation {
     substituteInPlace "$out/lib/pkgconfig/dri.pc" --replace '$(drivers)' "${driverLink}"
   '' + /* move vdpau drivers to $drivers/lib, so they are found */ ''
     mv "$drivers"/lib/vdpau/* "$drivers"/lib/ && rmdir "$drivers"/lib/vdpau
-  '' + /* add libGL* links from /run/opengl-driver */ ''
-    (
-      cd "$drivers/lib"
-      cp -s "$out"/lib/*.so .
-    )
   '';
   #ToDo: @vcunat isn't sure if drirc will be found when in $out/etc/, but it doesn't seem important ATM