hir: Refactor getters for HIR parents See individual commits. I ended up removing on of the FIXMEs from https://github.com/rust-lang/rust/pull/120206 instead of addressing it.
hir: Refactor getters for HIR parents See individual commits. I ended up removing on of the FIXMEs from https://github.com/rust-lang/rust/pull/120206 instead of addressing it.