patch 9.1.1285: Vim9: no error message for missing method after "super."

Problem:  Vim9: no error message for missing method after "super."
Solution: output an error message, add a few more tests
          (Yegappan Lakshmanan).

closes: #17070

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim9expr.c b/src/vim9expr.c
index 0ceff0b..40c5fcc 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -404,7 +404,10 @@
     char_u *name = *arg;
     char_u *name_end = find_name_end(name, NULL, NULL, FNE_CHECK_START);
     if (name_end == name)
+    {
+	emsg(_(e_missing_name_after_dot));
 	return FAIL;
+    }
     size_t len = name_end - name;
 
     if (*name_end == '(')