go-llvm/llvm appears to be a set of Go bindings to LLVM, i.e., the ability to access libllvm (embed LLVM and use it programatically) from a normal Go program. That is, you're using Go to drive LLVM, not LLVM to compile Go.

See the factorial example, where they build up some LLVM IR (in memory) for computing factorials: https://github.com/go-llvm/llvm/blob/master/examples/factori...

I'd guess the advantage of this is using LLVM's JIT at runtime.