The current mkdeps.bash just checks for dependencies for GOOS=windows
with the current GOARCH.  This is not always accurate as some package
imports only happen on specific GOOS/GOARCH combinations.  Check a
selected, easily changed, combination of GOOS/GOARCH values.

This generates a deps.go identical to the one in the repository today.

Fixes #13221.

Change-Id: I96d67d49c8c63641d578acedbb28be807607db65
Reviewed-on: https://go-review.googlesource.com/16882Reviewed-by: Michael Matloob <matloob@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>