Fix diffing locally deleted nodes that happen to be directly below
directories that were copied, but via the default ignore-ancestry
handling processed as if they exist in the repository.
(Yes, hard to explain... see testcase added in r1605810,r1605813)

The more common case of nodes that were deeper below such directories
use the standard local diff code which has much better test coverage.

* subversion/libsvn_wc/diff_editor.c
  (walk_local_nodes_diff): Properly handle svn_wc__db_status_deleted when there
    is no base node.

* subversion/tests/cmdline/diff_tests.py
  (diff_deleted_in_move_against_repos): Remove XFail marker.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1605832 13f79535-47bb-0310-9956-ffa450edef68