Track performance of core functions

[corasaurus-hex]

It would be nice if we could track performance of core functions across releases/commits in order to prevent performance regressions and more easily test performance improvements. I know some languages do this with rather elaborate suites but even something simple to easily compare performance would be great.

I've used https://benchmarkjs.com/ to do testing in Clava locally but I don't know what else is out there.

[borkdude]

Moving this to a discussion / idea until we have a concrete plan how to do it.