mesa: misc GLX_INTEL_swap_event fixes

Fixup a few issues found through testing:
  - update GLX names to match glproto
  - register DRI2WireToEvent so it actually gets called

Signed-off-by: Robert Bragg <robert@linux.intel.com>

include/GL/glx.h

@@ -518,8 +518,12 @@ typedef struct {
 } GLXPbufferClobberEvent;
 
 typedef struct {
+    int type;
+    unsigned long serial;	/* # of last request processed by server */
+    Bool send_event;		/* true if this came from a SendEvent request */
+    Display *display;		/* Display the event was read from */
+    GLXDrawable drawable;	/* drawable on which event was requested in event mask */
     int event_type;
-    GLXDrawable drawable;
     int64_t ust;
     int64_t msc;
     int64_t sbc;