Make all our package sources use Go 1.17 gofmt format (adding //go:build lines). Not strictly necessary but will avoid spurious changes as files are edited. Part of //go:build change (#41184). See https://golang.org/design/draft-gobuild Change-Id: I70526bf588bf4078887e567795867ece785d666b Reviewed-on: https://go-review.googlesource.com/c/crypto/+/294415 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>