Merge branch 'en/ort-perf-batch-14'
Further optimization on "merge -sort" backend.
* en/ort-perf-batch-14:
merge-ort: restart merge with cached renames to reduce process entry cost
merge-ort: avoid recursing into directories when we don't need to
merge-ort: defer recursing into directories when merge base is matched
merge-ort: add a handle_deferred_entries() helper function
merge-ort: add data structures for allowable trivial directory resolves
merge-ort: add some more explanations in collect_merge_info_callback()
merge-ort: resolve paths early when we have sufficient information