Update golang.org/x dependencies to their latest tagged versions.

Change-Id: I705c0d75bcc979d8c45266ba2e43b97cbf98e701
Reviewed-on: https://go-review.googlesource.com/c/tools/+/533240
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Gopher Robot <gobot@golang.org>