Recent work on `git-rebase--interactive` aims to convert shell code to
C. Even if this is most likely not a big performance enhancement, let's
convert it too since a coming change to abbreviate command names
requires it to be updated.
Signed-off-by: Liam Beguin <liambeguin@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>