patch 8.2.4037: Insert mode completion is insufficiently tested

Problem:    Insert mode completion is insufficiently tested.
Solution:   Add more tests.  Fix uncovered memory leak. (Yegappan Lakshmanan,
            closes #9489)
diff --git a/src/version.c b/src/version.c
index e86bd10..9d568b6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4037,
+/**/
     4036,
 /**/
     4035,