Add a new XFail test, reproducing a missing node error reported when diffing
a replaced node below a copy or move against a repository location.

Found by: stsp

* subversion/tests/cmdline/diff_tests.py
  (diff_replaced_moved): New test.
  (test_list): Add diff_replaced_moved.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1605866 13f79535-47bb-0310-9956-ffa450edef68