LUCENE-5263: fix cases where transient IOExc (e.g. due to disk full, file descriptor exhaustion) in IndexWriter could lead to silently losing deletions

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1530416 13f79535-47bb-0310-9956-ffa450edef68