Add _XITYPEDEF_POINTER to dix-config.h

Just like the pointer type from Xdefs.h, the Pointer type from
XIproto.h collides with local declarations of variables using the same
name. XIproto.h can use _XITYPEDEF_POINTER to avoid declaring the
unnecessary pointer type.

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

include/dix-config.h.in

@@ -472,6 +472,9 @@
 /* Don't let Xdefs.h define 'pointer' */
 #define _XTYPEDEF_POINTER       1
 
+/* Don't let XIproto define 'Pointer' */
+#define _XITYPEDEF_POINTER      1
+
 /* Ask fontsproto to make font path element names const */
 #define FONT_PATH_ELEMENT_NAME_CONST    1