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

Change-Id: I1b83f9faaac54edf433904ac46263cc4fc353012
Reviewed-on: https://go-review.googlesource.com/c/text/+/669917
Auto-Submit: Gopher Robot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: David Chase <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>