Re: [PATCH 02/18] Add a new builtin: branch-diff

This builtin does not do a whole lot so far, apart from showing a usage
that is oddly similar to that of `git tbdiff`. And for a good reason:
the next commits will turn `branch-diff` into a full-blown replacement
for `tbdiff`.

At this point, we ignore tbdiff's color options, as they will all be
implemented later and require some patches to the diff machinery.

Signed-off-by: Johannes Schindelin <redacted>
---

diff --git a/builtin/branch-diff.c b/builtin/branch-diff.c

@@ -0,0 +1,40 @@
+static const char * const builtin_branch_diff_usage[] = {
+       N_("git rebase--helper [<options>] ( A..B C..D | A...B | base A B )"),
+       NULL
+};