Auto merge of #142074 - oli-obk:its-finally-gone, r=petrochenkov

Remove CollectItemTypesVisitor

I always felt like we were very unnecessarily walking the HIR, let's see if perf agrees

There is lots to ~~improve~~ consolidate further here, as we still have 3 item wfchecks:

* check_item (matching on the hir::ItemKind)
    * actually doing trait solver based checks (by using HIR spans)
* lower_item (matching on the hir::ItemKind after loading it again??)
    * just ensure_ok-ing a bunch of queries
* check_item_type (matching on DefKind)
    * some type based checks, mostly ensure_ok-ing a bunch of queries

fixes rust-lang/rust#121429

1 files changed, 9 insertions, 0 deletions

diff --git a/compiler/rustc_middle/src/hir/mod.rs b/compiler/rustc_middle/src/hir/mod.rs
index a28dcb0cb8e..d1f5caaafb2 100644
--- a/compiler/rustc_middle/src/hir/mod.rs
+++ b/compiler/rustc_middle/src/hir/mod.rs
@@ -71,6 +71,7 @@ impl ModuleItems {
         self.opaques.iter().copied()
     }
 
+    /// Closures and inline consts
     pub fn nested_bodies(&self) -> impl Iterator<Item = LocalDefId> {
         self.nested_bodies.iter().copied()
     }
@@ -79,6 +80,14 @@ impl ModuleItems {
         self.owners().map(|id| id.def_id)
     }
 
+    /// Closures and inline consts
+    pub fn par_nested_bodies(
+        &self,
+        f: impl Fn(LocalDefId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,
+    ) -> Result<(), ErrorGuaranteed> {
+        try_par_for_each_in(&self.nested_bodies[..], |&&id| f(id))
+    }
+
     pub fn par_items(
         &self,
         f: impl Fn(ItemId) -> Result<(), ErrorGuaranteed> + DynSend + DynSync,