test-status: add test for removed-and-untracked state (BC)

In Mercurial 3.0, "hg status" can list the same file twice if it was removed
but still exists in working directory, i.e. removed by "hg forget":

  $ hg status --rev 0 removed
  R removed
  ? removed

But since 65cdc6bab91e, untracked state, "?", is no longer displayed in this
example.

I think the new behavior is correct since a file should have single state, but
if it is a bug, this patch should be dropped.

tests/test-status.t

@@ -280,6 +280,13 b' hg status -A --change 1 and revset:'
   R removed
   C deleted
 
+status of removed but existing in working directory.  "? removed" should
+not be included:
+
+  $ touch removed
+  $ hg status --rev 0 removed
+  R removed
+
   $ cd ..
 
 hg status of binary file starting with '\1\n', a separator for metadata: