How to get rid of "_ZL10nimZeroMemPvl" in an embedded target?

[dwhall256]

Thank you, @choltreppe. I got a chuckle (at my own expense) for trying to 
create "distinct generics". Once I realized the contradiction there and 
realized that creating subtypes of `Register[uint32, uint32]` would satisfy the 
type safety I'm seeking, the solution naturally fell out: 
<https://play.nim-lang.org/#ix=4Kmz>