Re: [PATCH v6 4/9] pack-objects: declare 'rev_info' for '--stdin-packs' earlier

> Once 'read_packs_list_from_stdin()' has called for_each_object_in_pack()
> on each of the input packs, we do a reachability traversal to discover
> names for any objects we picked up so we can generate name hash values
> and hopefully get higher quality deltas as a result.
>
> A future commit will change the purpose of this reachability traversal
> to find and pack objects which are reachable from commits in the input
> packs, but are packed in an unknown (not included nor excluded) pack.
>
> Extract the code which initializes and performs the reachability
> traversal to take place in the caller, not the callee, which prepares us
> to share this code for the '--unpacked' case (see the function
> add_unreachable_loose_objects() for more details).
>
> Signed-off-by: Taylor Blau <me@ttaylorr.com>
> ---
>  builtin/pack-objects.c | 71 +++++++++++++++++++++---------------------
>  1 file changed, 36 insertions(+), 35 deletions(-)