Merge branch 'jk/repack-tempfile-cleanup'

Merge branch 'jk/repack-tempfile-cleanup'

The way "git repack" creared temporary files when it received a
signal was prone to deadlocking, which has been corrected.

* jk/repack-tempfile-cleanup:
  t7700: annotate cruft-pack failure with ok=sigpipe
  repack: drop remove_temporary_files()
  repack: use tempfiles for signal cleanup
  repack: expand error message for missing pack files
  repack: populate extension bits incrementally
  repack: convert "names" util bitfield to array