The old name does not really say that this is about 'checkout -b'. See
49d833dc07 (Revert "checkout branch: prime cache-tree fully" -
2009-05-12) for more information
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>