patch 8.0.0169: json_decode() may run out of stack space

Problem:    For complicated string json_decode() may run out of stack space.
Solution:   Change the recursive solution into an iterative solution.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    169,
 /**/
     168,
 /**/