Add an XFAIL test for issue 4340, "repos layer should reject filenames with
trailing \n". 

* subversion/tests/libsvn_repos/repos-test.c
  (filename_trailing_newline, test_funcs): New test.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1461535 13f79535-47bb-0310-9956-ffa450edef68