Note that this does not run Go on the robot, it runs Go on a host computer and communicates with the robot with Firmata.
https://github.com/paypal/gatt
A writeup of their talk at GopherCon: http://gophercon.sourcegraph.com/post/83731231041/bluetooth-...
ARM is more promising with something like the Cortex M0+, but even then there are hurdles like the runtime size.