die() messages are traced in trace2, but BUG() messages are not. Anyone
tracking die() messages would have even more reason to track BUG().
Therefore, write to trace2 when BUG() is invoked.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>