patch 8.2.0683: Vim9: parsing type does not always work

Problem:    Vim9: parsing type does not always work.
Solution:   Handle func type without return value.  Test more closures.
            Fix type check offset.  Fix garbage collection.

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    683,
 /**/
     682,
 /**/