dri3: Enable GLX_INTEL_swap_event

Now that we're tracking SBC values correctly, and the X server has the
ability to send the GLX swap events from a PresentPixmap request, enable
this extension.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
1 file changed