Keep the previous behavior of `register_res`
Keep the previous behavior of `register_res`

Now that we're returning the `Res` of the associated item,
not the trait itself, it got confused.

graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust