patch 8.2.2519: Vim9: no reason to keep strange Vi behavior

Problem:    Vim9: no reason to keep strange Vi behavior.
Solution:   ":3" and ":3|" both go to line 3. ":|" does not print the line.
            (closes #7840)
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index 0becc7d..922080d 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -22,6 +22,17 @@
   :3
   list
   assert_equal('three$', Screenline(&lines))
+
+  # missing command does not print the line
+  var lines =<< trim END
+    vim9script
+    :1|
+    assert_equal('three$', Screenline(&lines))
+    :|
+    assert_equal('three$', Screenline(&lines))
+  END
+  CheckScriptSuccess(lines)
+
   bwipe!
 
   # won't generate anything