Add support for building the Xorg state tracker with scons.
scons ... statetrackers=xorg
diff --git a/src/gallium/SConscript b/src/gallium/SConscript
index 32b7c29..89c69d7 100644
--- a/src/gallium/SConscript
+++ b/src/gallium/SConscript
@@ -31,6 +31,7 @@
SConscript('state_trackers/python/SConscript')
SConscript('state_trackers/glx/xlib/SConscript')
SConscript('state_trackers/dri/SConscript')
+SConscript('state_trackers/xorg/SConscript')
if platform == 'windows':
SConscript('state_trackers/wgl/SConscript')