These have been unused since CL 10316.

Passes toolstash -cmp.

Change-Id: Icc19f3fcc7275fbee1c665f704e10a110ecce2a5
Reviewed-on: https://go-review.googlesource.com/21242Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Austin Clements <austin@google.com>