patch 8.2.3944: insert mode completion functions are too long

Problem:    Insert mode completion functions are too long.
Solution:   Split up into multiple functions. (Yegappan Lakshmanan,
            closes #9431)
diff --git a/src/version.c b/src/version.c
index c7644a4..f5f3c30 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3944,
+/**/
     3943,
 /**/
     3942,