Merge branch 'ds/mergies-with-sparse-index'

Various mergy operations have been prepared to work efficiently
with the sparse index.

* ds/mergies-with-sparse-index:
  sparse-index: integrate with cherry-pick and rebase
  sequencer: ensure full index if not ORT strategy
  t1092: add cherry-pick, rebase tests
  merge-ort: expand only for out-of-cone conflicts
  merge: make sparse-aware with ORT
  diff: ignore sparse paths in diffstat

diff --cc builtin/merge.c
Simple merge

diff --cc builtin/rebase.c
Simple merge

diff --cc builtin/revert.c
Simple merge

diff --cc merge-ort.c
Simple merge

diff --cc merge-recursive.c
Simple merge

diff --cc sequencer.c
Simple merge