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

Change-Id: If6f30243f94e503d7457bc6f595e02366c5b7ec4
Reviewed-on: https://go-review.googlesource.com/c/tools/+/617660
Reviewed-by: David Chase <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Auto-Submit: Gopher Robot <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>