virtualbox: Add ability to disable 32-bit guest support

pkgs/applications/virtualization/virtualbox/default.nix

@@ -9,6 +9,7 @@
 , pulseSupport ? false, libpulseaudio ? null
 , enableHardening ? false
 , headless ? false
+, enable32bitGuests ? true
 , patchelfUnstable # needed until 0.10 is released
 }:
 
@@ -128,6 +129,7 @@ in stdenv.mkDerivation {
       ${optionalString (!pythonBindings) "--disable-python"} \
       ${optionalString (!pulseSupport) "--disable-pulse"} \
       ${optionalString (!enableHardening) "--disable-hardening"} \
+      ${optionalString (!enable32bitGuests) "--disable-vmmraw"} \
       --disable-kmods --with-mkisofs=${xorriso}/bin/xorrisofs
     sed -e 's@PKG_CONFIG_PATH=.*@PKG_CONFIG_PATH=${libIDL}/lib/pkgconfig:${glib.dev}/lib/pkgconfig ${libIDL}/bin/libIDL-config-2@' \
         -i AutoConfig.kmk