Inner `go` functions obfuscate the generated Core

[sjakobi]

In the generated Core for D.HM.Internal or the new fine-grained benchmarks, I see a lot of $wgo3 and $wpoly_go11s where I have a hard time figuring out which function they are generated from.

This makes it significantly harder to understand and evaluate the performance characteristics of our code.

Therefore I think it would be useful to give these inner loops unique names that hint at the enclosing functions.