Consider "slow" protobuf as a build tag

[fdymylja]

Whilst iterating over the official goproto repo, many developers asked for reasons for which code generation fast paths (specifically related to marshalling/unmarshalling) implementation were never done. One of the answers given by the owners was that the big code size was a problem for some environments.

Might this something we need to consider in the scope of the cosmos ecosystem?

A solution could be generating a build tag for slow paths, ex:

types.slow.pb.go

// +build slow

... reflection code...

types.pb.go

// +build !slow
.. fast path code ...

[aaronc]

Sounds like a great idea!