The ARM port has improved greatly from how it was before Go1 (and even more so from where it was when Go was first announced).
x64 is still the best supported arch, but everything should work on ARM fine (and quite a few optimizations have gone into that port recently, but you will need to build from the tip for that).
I'm still using Lua in embedded projects. It's nice, nixio libs make is very nice and integrates with C ever so easily when needed.