Avoid `Lrc<Box<dyn CodegenBackend>>`. Because `Lrc<Box<T>>` is silly. (Clippy warns about `Rc<Box<T>>` and `Arc<Box<T>>`, and it would warn here if (a) we used Clippy with rustc, and (b) Clippy knew about `Lrc`.) r? `@bjorn3`
Avoid `Lrc<Box<dyn CodegenBackend>>`. Because `Lrc<Box<T>>` is silly. (Clippy warns about `Rc<Box<T>>` and `Arc<Box<T>>`, and it would warn here if (a) we used Clippy with rustc, and (b) Clippy knew about `Lrc`.) r? `@bjorn3`