Merge branch 'sb/repack-in-c'

"git repack --max-pack-size=8g" stopped being parsed correctly when
the command was reimplemented in C.

* sb/repack-in-c:
repack: propagate pack-objects options as strings
repack: make parsed string options const-correct
repack: fix typo in max-pack-size option

diff --cc builtin/repack.c
Simple merge