Get rid of residue after removing old parser.

Change-Id: I0dace1037d50959071a082c276f9f374eef6edb2
Reviewed-on: https://go-review.googlesource.com/17179
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>