We have different deps depending on the platform.
If we pick a privileged platform, we'll miss some deps.
If we use the union of all platforms, the integration test
won't compile on some platforms, because it'll import
packages that don't compile on that platform.
Give in to the madness and give each platform its own deps file.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
It was caching too aggressively, as it didn't see our deps due to our
running "go install tailscaled" as a child process.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>