cmd/vet/all still doesn't run for mips/mipsle,
because the rest of the toolchain doesn't yet
fully support it.

Change-Id: I1a86b0edddbdcd5f43e752208508d99da7aabbb3
Reviewed-on: https://go-review.googlesource.com/33134
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>