Auto merge of #95655 - kckeiks:create-hir-crate-items-query, r=cjgillot

Refactor HIR item-like traversal (part 1)

Issue  #95004

- Create hir_crate_items query which traverses tcx.hir_crate(()).owners to return a hir::ModuleItems
- use tcx.hir_crate_items in tcx.hir().items() to return an iterator of hir::ItemId
- use tcx.hir_crate_items to introduce a tcx.hir().par_items(impl Fn(hir::ItemId)) to traverse all items in parallel;

Signed-off-by: Miguel Guarniz <mi9uel9@gmail.com>

cc `@cjgillot`

compiler/rustc_interface/src/proc_macro_decls.rs

@@ -1,35 +1,25 @@
 use rustc_hir as hir;
 use rustc_hir::def_id::LocalDefId;
-use rustc_hir::itemlikevisit::ItemLikeVisitor;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::sym;
 
 fn proc_macro_decls_static(tcx: TyCtxt<'_>, (): ()) -> Option<LocalDefId> {
     let mut finder = Finder { tcx, decls: None };
-    tcx.hir().visit_all_item_likes(&mut finder);
 
-    finder.decls.map(|id| tcx.hir().local_def_id(id))
+    for id in tcx.hir().items() {
+        let attrs = finder.tcx.hir().attrs(id.hir_id());
+        if finder.tcx.sess.contains_name(attrs, sym::rustc_proc_macro_decls) {
+            finder.decls = Some(id.def_id);
+        }
+    }
+
+    finder.decls
 }
 
 struct Finder<'tcx> {
     tcx: TyCtxt<'tcx>,
-    decls: Option<hir::HirId>,
-}
-
-impl<'v> ItemLikeVisitor<'v> for Finder<'_> {
-    fn visit_item(&mut self, item: &hir::Item<'_>) {
-        let attrs = self.tcx.hir().attrs(item.hir_id());
-        if self.tcx.sess.contains_name(attrs, sym::rustc_proc_macro_decls) {
-            self.decls = Some(item.hir_id());
-        }
-    }
-
-    fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem<'_>) {}
-
-    fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {}
-
-    fn visit_foreign_item(&mut self, _foreign_item: &hir::ForeignItem<'_>) {}
+    decls: Option<hir::def_id::LocalDefId>,
 }
 
 pub(crate) fn provide(providers: &mut Providers) {