These tests tried to access the user's GOPATH, which can't work if you're
running from a module! So use packagestest to set up a fake GOPATH.
Also remove a TODO that's never going to be done because we won't
be making more investments in go/build.
Change-Id: I379c74345ace91e6c4282a42ff62106bf325d0e0
Reviewed-on: https://go-review.googlesource.com/c/162757
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
4ea155ddbd