48e47a6889
Add `Debug` impls to API types in `rustc_codegen_ssa` Some types used in `rustc_codegen_ssa`'s interface traits are missing `Debug` impls. Though I did not smear `#[derive(Debug)]` all over the crate (some structs are quite large).
Please read the rustc-dev-guide chapter on Backend Agnostic Codegen.