Add ChakraCore testing facilities
It is trivial to get pre-built ChakraCore binaries. This ticket asks that support for ChakraCore be added to script/test and others so that it is easy for users to also test with this engine if desired. The amount of time needed to run the tests is not significantly more than the other fast engines.
Attached re-baselined CLJS-2192-v2.patch.
The patch needs to be rebased to master.
Attached patch adds ChakraCore to the test scripts, including (and tested on) Windows.
The tests pass on macOS and Linux, but fail on Windows in a 3 spots (will deal with those few failures via separate ticket or tickets).
Also adds ChakraCore to CI (it passes there).