Update to the latest version of LLVMCMakeTemplate

[mrexodia]

This uses Hunter to automatically download/compile/install LLVM in HUNTER_ROOT.

Probably needs some testing, because when running llvm8.exe --rom ./roms/boot.ch8 --code "0-88" it crashed, but it should work:tm:

[ioncodes]

Will check this out ASAP! Thanks a lot :)