Don’t use `type Error = !` for target-dependant TryFrom impls.
Don’t use `type Error = !` for target-dependant TryFrom impls.

Instead, expose apparently-fallible conversions in cases where
the implementation happens to be infallible for a given target.

Having an associated type / return type in a public API change
based on the target is a portability hazard.

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