Move methods from Map to TyCtxt, part 4.

Continuing the work from #137350.

Removes the unused methods: `expect_variant`, `expect_field`,
`expect_foreign_item`.

Every method gains a `hir_` prefix.

compiler/rustc_lint/src/late.rs

@@ -48,7 +48,7 @@ impl<'tcx, T: LateLintPass<'tcx>> LateContextAndPass<'tcx, T> {
     where
         F: FnOnce(&mut Self),
     {
-        let attrs = self.context.tcx.hir().attrs(id);
+        let attrs = self.context.tcx.hir_attrs(id);
         let prev = self.context.last_node_with_lint_attrs;
         self.context.last_node_with_lint_attrs = id;
         debug!("late context: enter_attrs({:?})", attrs);