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

Change-Id: Ia362a291d4c1bad04462b136af09f630c1b5bb05
Reviewed-on: https://go-review.googlesource.com/c/tools/+/596897
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Gopher Robot <gobot@golang.org>