builtin-am: invoke post-rewrite hook
builtin-am: invoke post-rewrite hook

Since 96e1948 (rebase: invoke post-rewrite hook, 2010-03-12), git-am.sh
will invoke the post-rewrite hook after it successfully finishes
applying all the queued patches.

To do this, when parsing a mail to extract its patch and metadata, in
--rebasing mode git-am.sh will also store the original commit ID in the
$state_dir/original-commit file. Once it applies and commits the patch,
the original commit ID, and the new commit ID, will be appended to the
$state_dir/rewritten file.

Once all of the queued mail have been processed, git-am.sh will then
invoke the post-rewrite hook with the contents of the
$state_dir/rewritten file.

Re-implement this in builtin/am.c.

Signed-off-by: Paul Tan <ca5433e1cdd25b4a4001c54525dea593b33edc0c@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git