Per JBTM-602, we need to correlate recovery scan results for the same RM even when these are obtained using different XAResource/Connection instances. The current algorithm for this walks the old scans and replaces the stale XAResource with the newer one where Xids from the two scans match. However, this is insufficient as one or both passes may have resulted in an empty set of Xids. Update matching to fallback to using isSameRM when Xid matching is not possible, in order to increase robustness where one or both scans have empty results.