cmd/tailscale: make ssh command prefer Windows ssh.exe over PATH Signed-off-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>
Adds a stub for syscall.Exec when GOOS=js. We also had a separate branch for Windows, might as well use the same mechanism there too. For #3157 Signed-off-by: Mihai Parparita <mihai@tailscale.com>