Hi,

With this patch I'm not sure how to properly handle Copyright. I've 
taken a guess and prepared a
patch anyway.

Here's the situation.

Updating to 1.8 was not trivial. A fix has been posted in a comment by 
Sergei Trofimovich on
github[1]. It's a proper Guix patch, updating Go to 1.8, with the fix 
and the trivial update stuff,
but as far as I can see not actually submitted to Guix.

[1] https://github.com/golang/go/issues/19132#issuecomment-285897612

After this Go 1.8.1 has been released. The attached patch has the 
trivial update stuff for 1.8.1
and the fix by Sergei. I added Sergei to the Copyright section, but I'm 
not sure if this is
correct, and if this is the way to do it. Also, I didn't find his e-mail 
address, so I just added
his github page, in ()...

A little messy, please let me know if I should do something differently.

Best,
Petter