patch 8.2.1934: Vim9: command modifiers in :def function not tested

Problem:    Vim9: command modifiers in :def function not tested.
Solution:   Add tests.  Fix using modifier before filter command.
diff --git a/src/version.c b/src/version.c
index ca98d24..a0c3857 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1934,
+/**/
     1933,
 /**/
     1932,