patch 8.2.3852: Vim9: not enough tests

Problem:    Vim9: not enough tests.
Solution:   Also run existing tests for Vim9 script.  Make errors more
            consistent.
diff --git a/src/version.c b/src/version.c
index d65a5c1..288b23a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3852,
+/**/
     3851,
 /**/
     3850,