patch 9.0.1719: if_lua: crash for for Lua functions invoked via Vim callbacks

Problem: if_lua: crash for Lua functions invoked via Vim callbacks
Solution: Use Lua registry rather than upvalues for udata cache

closes: #12785

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Jesse Pavel <jpavel@alum.mit.edu>

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1719,
 /**/
     1718,
 /**/