Follow-up to r958881. Use --git-diff flag when invoking 'svn diff'. 
Follow-up to r958881. Use --git-diff flag when invoking 'svn diff'. 

* subversion/tests/cmdline/diff_tests.py
  (diff_git_format_wc_wc,
   diff_git_format_url_wc,
   diff_git_format_url_url): Call svn diff with the --git-diff flag. Remove
    note about the need to define SVN_EXPERIMENTAL_PATCH.
  (test_list): Remove XFail markers.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion