Not used any more.

Fixes #53860

Change-Id: Id0b1c3ed30b576d6c5f08f064d1262de337262b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/418374


Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>