Add a simple directory rename testcase, in conjunction with each of the
types of rebases:
git-rebase--interactive
git-rebase--am
git-rebase--merge
and also use the same testcase for
git am --3way
This demonstrates a difference in behavior between the different rebase
backends in regards to directory rename detection.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>