Added non-reflection select statements to Go benchmark

The doc string in the Go benchmark says that you considered whether to benchmark against the select statement vs reflection. I think it should definitely include the idiomatic Go select statement approach as a realistic comparison. Otherwise it is like the language benchmarks that write each benchmark using only the style of one language (i.e. comparing to Java and writing Go like it is Java, etc). No point in using a crippled version of the Go benchmark only because it most closely matches the way you were able to implement the semantics in Python.