scratch/xiam: add main.go file.
scratch/xiam: add main.go file.

Change-Id: If63481354adf6f47fb4fb17ef171afc566ac8d1a
Reviewed-on: https://go-review.googlesource.com/48723
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: Han-Wen Nienhuys <3269a793d567baa2fa5b041e3e5e0a5039790a2f@google.com>

golang/scratch