Separating the C++ wasm runtime repo and the benchmarks

[mike-lischke]

I just fixed the repo to allow executing the benchmarks again (which I broke in a previous clean up step). @jimidle I don't know if you already started with Go and Java benchmarks, but I want to let you know that I plan to separate benchmarks and C++ wasm repo. So, if you have started already it might better to open a pull request now, even if not everything is in place.

Otherwise let me do the separation first.

[jimidle]

I had started on the Go stuff, but it is trivial to just transfer that to anywhere you end up. Don't worry about me. I had time set aside for this stuff and upgrading the go runtime, but then Eric made me join Toptal and I have been filling out forms and umpteen copes of resumes. Do what you need to do and then just let me know where to put my Go stuff afterwards. No problem.