Run against the tc39 testsuite

[mstoykov]

This is already being done by goja here but arguably we can do it as well but with a newer version (we have string literals from babel which is the reason why goja is stuck to a version from 2017) and with more of the tests as again babel provides us with support for more of them.

I would also argue that we should run the WHOLE suite and codify the things that don't work so when they start work we actually find this out, through the tests breaking.

Given that this is likely to take a LOT of time on each run maybe we should break them apart in es5, es6, es7 ... test packages and probably run them in a separate runner in CI and maybe not locally, although of course that depends on just how slow it's going to be.

[mstoykov]

This currently is being worked on at https://github.com/MStoykov/k6-test262

[mstoykov]

closed with #1747