[PATCH] GLX/DRI2: Do not expose INTEL_swap_event without swap control

[Zack Rusin]

> Swap events depent on the implementation of ScheduleSwap. By
> unconditionally enabling GLX_INTEL_swap_event we're breaking
> the system with drivers that don't support it because the apps
> are forever stuck waiting for an event that will never be
> delivered. So lets enable the extension only if the hooks it
> depends on are actually there.

Ping. Can someone please review/push this? It's quite important.


z