patch 8.2.4001: insert complete code uses global variables

Problem:    Insert complete code uses global variables.
Solution:   Make variables local to the file and use accessor functions.
            (Yegappan Lakshmanan, closes #9470)
diff --git a/src/version.c b/src/version.c
index 83e054a..e4c5bb8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4001,
+/**/
     4000,
 /**/
     3999,