open files limit

Somebody at $work found this problem:

    $ git ls-files -s | wc
    error: packfile .git/objects/pack/pack-1627e77da82bbb36118762649c8aa88c05664b1e.pack cannot be accessed
    [..lots more similar errors..]

Turns out his shell's open file descriptor limit was 500.  And
there are 1600 pack files in the repo.

Increasing the descriptor limit to 1024 fixed it.  I could
probably get him to repack, which may also fix it.

Does it seem feasible to look for EMFILE errors and close
some packs?  Or at least spit out a more intuitive error?

		-- Pete