PPU LLVM JIT Repository Early Testing

To be clear Gopalsr83 has merged master in his branch and not the other way around. We don't have it master for multiple reasons. First of all, there hasn't been a pull-request (I assume Gopalsr wants to make it more feature-complete first).

Secondly, llvm is a huge dependency and there is rightful concern of having too many dependencies (I didn't even get granted Boost ). Not to mention that we already depend on ASMJIT which is partially duplication in functionality.

If the llvm dependency were optional (i.e. you can still compile without llvm but you would not get the recompiler option) this would an easier decision but as it stands merging the branch requires some actual discussion of the merits.