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

Change-Id: I6836e5dc5d77c3296197b39403d6f987843017be
Reviewed-on: https://go-review.googlesource.com/c/tools/+/583536
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>