Merge branch 'jk/pack-bitmap'

* jk/pack-bitmap:
  pack-objects: do not reuse packfiles without --delta-base-offset
  add `ignore_missing_links` mode to revwalk

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

diff --cc list-objects.c
Simple merge

diff --cc revision.c
Simple merge

diff --cc revision.h
Simple merge