patch 8.1.0454: resolve() was not tested with a symlink cycle

Problem:    resolve() was not tested with a symlink cycle.
Solution:   Add a test. (Dominique Pelle, closes #3513)

src/version.c

@@ -792,6 +792,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    454,
 /**/
     453,
 /**/