patch 8.2.4573: a nested function is compiled for debugging without context

Problem:    A nested function (closure) is compiled for debugging without
            context.
Solution:   Check if a nested function is marked for debugging before
            compiling it.  Give an error when trying to compile a closure
            without its context. (closes #9951)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4573,
 /**/
     4572,
 /**/