Rollup merge of #137305 - nnethercote:rustc_middle-2, r=lcnr

Tweaks in and around `rustc_middle`

A bunch of tiny improvements I found while working on bigger things.

r? ```@lcnr```

clippy_lints/src/redundant_clone.rs

@@ -205,7 +205,7 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClone {
             let node = mir.source_scopes[scope]
                 .local_data
                 .as_ref()
-                .assert_crate_local()
+                .unwrap_crate_local()
                 .lint_root;
 
             if let Some(snip) = span.get_source_text(cx)