This is mostly to allow access to exported file contents for tests
that need the source.
Change-Id: I0ef946d7bdd971b931e509d2cb54e2c59649fe47
Reviewed-on: https://go-review.googlesource.com/c/tools/+/166883
Reviewed-by: Michael Matloob <matloob@golang.org>
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>