(WIP) Scratch LLVM front and backend
NOTE: I started this before looking at the size of the llvm documentation, and I'm busy working on other stuff, so it might be a while until anything appears here
I'm back to working on this! More stuff will appear soon...
Clang 4.0 or newer is needed to compile this, as this uses some c++17 features. You'll need to add -DCMAKE_CXX_FLAGS='-std=c++1z' to CMake.