Merge branch 'ps/object-info-bits-cleanup'

Merge branch 'ps/object-info-bits-cleanup'

A couple of bugs in use of flag bits around odb API has been
corrected, and the flag bits reordered.

* ps/object-info-bits-cleanup:
  odb: convert `odb_has_object()` flags into an enum
  odb: convert object info flags into an enum
  odb: drop gaps in object info flag values
  builtin/fsck: fix flags passed to `odb_has_object()`
  builtin/backfill: fix flags passed to `odb_has_object()`