Revert "glx: Remove pointless GLX_INTEL_swap_event paranoia"
Revert "glx: Remove pointless GLX_INTEL_swap_event paranoia"
This reverts commit 19c57ea3.
This commit is causing a reproducible crash of GNOME shell on Xorg server. Revert it for now and we may investigate it further in the future.
Fixes #8542 (closed).