Add support for Jackalope

[agroce]

https://github.com/googleprojectzero/Jackalope

Not quite working for me, yet, but it'd be nice to have a Mac os friendly first-class fuzzer, and the ability to control mutation/instrumentation more modularly sounds nice for us, as well. Given libfuzzer still isn't in apple clang, and installing a second clang can be a pain for people on mac, plus AFL slowness, might be worth having good support for this.

[agroce]

Ok, Jackalope used to fuzz a deepstate binary, at least