Improved Hermes ES6 score

[tmikov]

Hermes has two experimental options that can potentially improve the results: --block-scoping and -Xes6-class. How difficult would it be to pass them?

FWIW, it looks not exactly trivial. I think hermes is invoked from https://github.com/CanadaHonk/test262.fyi/blob/78cb8ddcf97cb42c3c40117d35bc6d484caf0437/.github/workflows/run.yml and I don't see an obvious way to pass special arguments there (but I know nothing about Git workflows). Perhaps an easier alternative would be to create a wrapper shell-script and invoke that?

[CanadaHonk]

I'm somewhat hesitant to add arguments which are not on by default for most cases, are the options commonly used / why are they off by default?