Thre are still two remaining compiler warnings, because of non matching
function prototypes and function pointer arguments prototypes:

src/XSndExEv.c:XSendExtensionEvent()
  variable register Status(**fp) (Display *, XEvent*, xEvent **, int *)
  doesn't match struct _XDisplay's:
  Status (*wire_vec[128])( /* vector for event to wire */
                Display *       /* dpy */,
                XEvent *        /* re */,
                xEvent *        /* event */
                );

and

src/XExtInt.c:xinput_extension_hooks field event_to_wire of type
  XExtensionHooks that has the prototype     Status (*event_to_wire)(
	      Display*			/* display */,
              XEvent*			/* re */,
              xEvent*			/* event */
  );
  does not match Status
  _XiEventToWire(
    register Display	 *dpy,		/* pointer to display structure */
    register XEvent	 *re,		/* pointer to client event */
    register xEvent	**event,	/* wire protocol event */
    register int	 *count);

Signed-off-by: Peter Hutterer <peter@cs.unisa.edu.au>