Merged revision(s) 1622999 from lucene/dev/trunk:
Fix test to abort, if filesystem does not support non-readable directories (e.g., windows).

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1623000 13f79535-47bb-0310-9956-ffa450edef68