This way we'll get the correct generated code comments.

Change-Id: I273cd16dcce99b49b6df0b86fc191b3ff5d7167a
Reviewed-on: https://go-review.googlesource.com/122458
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>