Expose test262 results with releases

I've been looking into your [test262](https://github.com/tc39/test262) compliance (official ECMAScript test suite), and I've seen your [blacklist file](https://github.com/facebook/hermes/blob/a311b71ce1333c1c7ee1454b0639ab7289a07514/utils/testsuite/testsuite_blacklist.py).

I totally get that this engine is very new and this is then a work in progress. But to better allow early-stage users to decide in which condition they should try it, I guess it would be very nice to expose the supported (and not supported) ECMAScript features as per the test262 full results.

Maybe could you even fill the [Kangax ECMAScript compatibility table](http://kangax.github.io/compat-table/es6/) with the results

Thanks