One of the fields of `TargetIsa` isn't used in the cranelift-codegen-meta crate, but instead of refactoring to try to remove it this just adds `#[allow(dead_code)]` for now in the assumption that when the old backends go away this will probably go away as well.
This crate contains the metaprogram used by cranelift-codegen. It's not useful on its own.