Output LLVM IR to file

Horrible hack around dump. Apparently RLTK's `Module#compile` and `Module#print` are broken, but dump still works. So, redirecting `$stderr` will have to suffice for now.
wrap call to llc

Necessary since `Module#compile` is broken.
Create executable by calling gcc

Final component of hacky replacement for `Module#compile`
some testing to make sure the plumbing is correct
modify path on travis