When two phase index builds are enabled, timestamp_index_builds.js currently fails in the third phase of the test where the node is restarted as a standalone node. The underlying issue seems to be that the completion of a two phase index build, represented in the oplog by the commitIndexBuild oplog entry, is not timestamped correctly. Currently, we obtain a ghost timestamp for the purposes of writing to the mdb catalog on a successful index build. Now that we have the commitIndexBuild oplog entry, we should be able use a timestamp that is present in the oplog.