temporarily fix clippy issues to run tests

Author: 1c3t3a

src/tools/clippy/clippy_lints/src/missing_const_for_fn.rs

@@ -154,10 +154,10 @@ impl<'tcx> LateLintPass<'tcx> for MissingConstForFn {
             return;
         }
 
-        let mir = cx.tcx.optimized_mir(def_id);
+        let mir = cx.tcx.mir_drops_elaborated_and_const_checked(def_id);
 
-        if let Ok(()) = is_min_const_fn(cx.tcx, mir, &self.msrv)
-            && let hir::Node::Item(hir::Item { vis_span, .. }) | hir::Node::ImplItem(hir::ImplItem { vis_span, .. }) =
+        if let Ok(()) = is_min_const_fn(cx.tcx,& mir.borrow(), &self.msrv)
+        && let hir::Node::Item(hir::Item { vis_span, .. }) | hir::Node::ImplItem(hir::ImplItem { vis_span, .. }) =
                 cx.tcx.hir_node_by_def_id(def_id)
         {
             let suggestion = if vis_span.is_empty() { "const " } else { " const" };