Remove box syntax from Box<rustdoc::clean::types::ItemKind> construction

The type has 240 bytes according to compiler internal rustdoc.

src/librustdoc/clean/inline.rs

@@ -538,7 +538,7 @@ fn build_module(
                     attrs: Box::new(clean::Attributes::default()),
                     item_id: ItemId::Primitive(prim_ty, did.krate),
                     visibility: clean::Public,
-                    kind: box clean::ImportItem(clean::Import::new_simple(
+                    kind: Box::new(clean::ImportItem(clean::Import::new_simple(
                         item.ident.name,
                         clean::ImportSource {
                             path: clean::Path {
@@ -554,7 +554,7 @@ fn build_module(
                             did: None,
                         },
                         true,
-                    )),
+                    ))),
                     cfg: None,
                 });
             } else if let Some(i) = try_inline(cx, did, None, res, item.ident.name, None, visited) {

src/librustdoc/clean/mod.rs

@@ -2108,7 +2108,7 @@ fn clean_extern_crate<'tcx>(
         attrs: Box::new(attrs.clean(cx)),
         item_id: crate_def_id.into(),
         visibility: clean_visibility(ty_vis),
-        kind: box ExternCrateItem { src: orig_name },
+        kind: Box::new(ExternCrateItem { src: orig_name }),
         cfg: attrs.cfg(cx.tcx, &cx.cache.hidden_cfg),
     }]
 }

src/librustdoc/clean/types.rs

@@ -502,7 +502,7 @@ impl Item {
             clean_visibility(cx.tcx.visibility(def_id))
         };
 
-        Item { item_id: def_id.into(), kind: box kind, name, attrs, visibility, cfg }
+        Item { item_id: def_id.into(), kind: Box::new(kind), name, attrs, visibility, cfg }
     }
 
     /// Finds all `doc` attributes as NameValues and returns their corresponding values, joined

src/librustdoc/fold.rs

@@ -2,7 +2,7 @@ use crate::clean::*;
 
 pub(crate) fn strip_item(mut item: Item) -> Item {
     if !matches!(*item.kind, StrippedItem(..)) {
-        item.kind = box StrippedItem(item.kind);
+        item.kind = Box::new(StrippedItem(item.kind));
     }
     item
 }
@@ -75,10 +75,10 @@ pub(crate) trait DocFolder: Sized {
 
     /// don't override!
     fn fold_item_recur(&mut self, mut item: Item) -> Item {
-        item.kind = box match *item.kind {
-            StrippedItem(box i) => StrippedItem(box self.fold_inner_recur(i)),
+        item.kind = Box::new(match *item.kind {
+            StrippedItem(box i) => StrippedItem(Box::new(self.fold_inner_recur(i))),
             _ => self.fold_inner_recur(*item.kind),
-        };
+        });
         item
     }