Add llvm-16 support - #2

LGTM. Considering the complexity of the build process for this repo and marvin-cxx, you might want to look into using a Nix flake for setting up the environment instead. While the Dockerfile will be the same for our cloud builds, having the ability to get your local setup running with just nix develop will make it a lot easier for others to hit the ground running if they decide to contribute to the analyzers!

For now local setup on Mac OS is as simple as the running the following commands

$ brew install llvm@16 && tack --build lta

where tack is Python script to invoke cmake after setting some envs.

I am yet to get a chance to use Nix but do they support installing latest version of llvm?

Yes, they do have llvm_16 on the Nix repository. But if the current script works, then we're good