Auto merge of #120943 - petrochenkov:somehir3, r=oli-obk

Create some minimal HIR for associated opaque types

`LocalDefId`s for opaque types in traits and impls are created after AST -> HIR lowering, so they don't have corresponding HIR and return their various properties through fed queries.

In this PR I also feed some core HIR-related queries for these `LocalDefId`s (which happen to be HIR owners).
As a result all `LocalDefId`s now have corresponding `HirId`s and HIR nodes, and "optional" methods like `opt_local_def_id_to_hir_id` and `opt_hir_node_by_def_id` can be removed.

Follow up to https://github.com/rust-lang/rust/pull/120206.

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -196,6 +196,7 @@ fn check_well_formed(tcx: TyCtxt<'_>, def_id: hir::OwnerId) -> Result<(), ErrorG
         hir::OwnerNode::TraitItem(item) => check_trait_item(tcx, item),
         hir::OwnerNode::ImplItem(item) => check_impl_item(tcx, item),
         hir::OwnerNode::ForeignItem(item) => check_foreign_item(tcx, item),
+        hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
     };
 
     if let Some(generics) = node.generics() {

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -262,6 +262,7 @@ fn resolve_bound_vars(tcx: TyCtxt<'_>, local_def_id: hir::OwnerId) -> ResolveBou
             visitor.visit_impl_item(item)
         }
         hir::OwnerNode::Crate(_) => {}
+        hir::OwnerNode::AssocOpaqueTy(..) => unreachable!(),
     }
 
     let mut rl = ResolveBoundVars::default();