Merge branch 'tb/pack-revindex-on-disk'

The on-disk reverse index that allows mapping from the pack offset
to the object name for the object stored at the offset has been
enabled by default.

* tb/pack-revindex-on-disk:
  t: invert `GIT_TEST_WRITE_REV_INDEX`
  config: enable `pack.writeReverseIndex` by default
  pack-revindex: introduce `pack.readReverseIndex`
  pack-revindex: introduce GIT_TEST_REV_INDEX_DIE_ON_DISK
  pack-revindex: make `load_pack_revindex` take a repository
  t5325: mark as leak-free
  pack-write.c: plug a leak in stage_tmp_packfiles()

diff --cc builtin/index-pack.c
Simple merge

diff --cc builtin/pack-objects.c
Simple merge

diff --cc pack-bitmap.c
Simple merge

diff --cc pack-revindex.c
Simple merge

diff --cc pack-write.c
Simple merge

diff --cc packfile.c
Simple merge