gdi32: Get rid of the RGNOBJ type, instead store a pointer to the region itself.

dlls/gdi32/gdi_private.h

@@ -349,7 +349,12 @@ typedef struct
     RECT *rects;
     RECT extents;
 } WINEREGION;
-extern const WINEREGION *get_wine_region(HRGN rgn) DECLSPEC_HIDDEN;
+
+/* return the region data without making a copy */
+static inline const WINEREGION *get_wine_region(HRGN rgn)
+{
+    return GDI_GetObjPtr( rgn, OBJ_REGION );
+}
 static inline void release_wine_region(HRGN rgn)
 {
     GDI_ReleaseObj(rgn);