Auto merge of #80014 - jyn514:box-item-kind, r=nnethercote

[rustdoc] Box ItemKind to reduce the size of `Item`

This brings the size of `Item` from

```
[src/librustdoc/lib.rs:103] std::mem::size_of::<Item>() = 536
```

to

```
[src/librustdoc/lib.rs:103] std::mem::size_of::<Item>() = 136
```

This is an alternative to https://github.com/rust-lang/rust/pull/79967; I don't think it makes sense to make both changes.

Helps with #79103.

2 files changed, 4 insertions, 4 deletions

diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 3b7ac624ccd..e347f7f8411 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -19,9 +19,9 @@ impl JsonRenderer<'_> {
         let item_type = ItemType::from(&item);
         let deprecation = item.deprecation(self.tcx);
         let clean::Item { source, name, attrs, kind, visibility, def_id } = item;
-        match kind {
+        match *kind {
             clean::StrippedItem(_) => None,
-            _ => Some(Item {
+            kind => Some(Item {
                 id: def_id.into(),
                 crate_id: def_id.krate.as_u32(),
                 name: name.map(|sym| sym.to_string()),
diff --git a/src/librustdoc/json/mod.rs b/src/librustdoc/json/mod.rs
index dc2bc14e7ce..df7ab9b7361 100644
--- a/src/librustdoc/json/mod.rs
+++ b/src/librustdoc/json/mod.rs
@@ -178,9 +178,9 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         cache: &Cache,
     ) -> Result<(), Error> {
         use clean::types::ItemKind::*;
-        if let ModuleItem(m) = &item.kind {
+        if let ModuleItem(m) = &*item.kind {
             for item in &m.items {
-                match &item.kind {
+                match &*item.kind {
                     // These don't have names so they don't get added to the output by default
                     ImportItem(_) => self.item(item.clone(), cache).unwrap(),
                     ExternCrateItem(_, _) => self.item(item.clone(), cache).unwrap(),