patch 8.2.4384: Vim9: error message not tested, some code not tested

Problem:    Vim9: error message not tested, some code not tested.
Solution:   Add a couple of test cases.  Give an error for a command modifier
            without a command.
diff --git a/src/version.c b/src/version.c
index d7cfb17..3716b3d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4384,
+/**/
     4383,
 /**/
     4382,