golang sha256block_amd64 代码
文件路径：/src/cmd/internal/notsha256/sha256block_amd64.go
/ Copyright 2017 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
/go:build !purego
/ +build !purego
package notsha256
var useAVX2 = false