Set up OSS-Fuzz

[Marcono1234]

What do you think about setting up OSS-Fuzz for this project?

Given that aircompressor uses sun.misc.Unsafe quite a lot, it is probably important that all of this usage is safe since otherwise the JVM could crash, or worse. OSS-Fuzz might be able to help find issues with that.

I assume aircompressor fulfills the requirements to be included into OSS-Fuzz, but that can also be clarified with the maintainers beforehand.

For Zstd it might be necessary to add a hook to disable checksum verification, otherwise fuzzing might not be that effective there, see jazzer documentation for some information. I don't have any experience with that yet.

Fuzzing with OSS-Fuzz / jazzer might not support detecting out-of-bounds Unsafe reads and writes yet though, see CodeIntelligenceTesting/jazzer#891.