CL 402595 changes all usages of 20 bytes hash to 32 bytes hash by using
notsha256.
However, since CL 454836, notsha256 is not necessary anymore, so this CL
reverts those changes to 20 bytes hash using cmd/internal/hash package.
Updates #51940
Updates #64751
Change-Id: Icb08d5a0d8032a3c4d050ff7b2298d31c483b88b
Reviewed-on: https://go-review.googlesource.com/c/go/+/610597 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Keith Randall <khr@golang.org>