Update runtime patch to the latest Go version

[ddska]

Could you update the runtime patch to the latest Go version (1.8.1 at the moment of writing this) please?

[divan]

@ddska yes, work in progress!

[divan]

@ddska the work is in https://github.com/divan/gotrace/tree/go18 branch. I'll be testing it for a while before merging to master, but you can play with this branch already.

[ddska]

Thank you, will try it.