let fn_id = tcx.hir().local_def_id_to_hir_id(fn_def.did);
let generator_kind = tcx.generator_kind(fn_def.did);
+ // The representation of thir for `-Zunpretty=thir-tree` relies on
+ // the entry expression being the last element of `thir.exprs`.
+ assert_eq!(expr.as_usize(), thir.exprs.len() - 1);
+
// Figure out what primary body this item has.
let body_id = tcx.hir().body_owned_by(fn_def.did);
let span_with_body = tcx.hir().span_with_body(fn_id);