Auto merge of #122077 - oli-obk:eager_opaque_checks4, r=lcnr

Pass list of defineable opaque types into canonical queries

This eliminates `DefiningAnchor::Bubble` for good and brings the old solver closer to the new one wrt cycles and nested obligations. At that point the difference between `DefiningAnchor::Bind([])` and `DefiningAnchor::Error` was academic. We only used the difference for some sanity checks, which actually had to be worked around in places, so I just removed `DefiningAnchor` entirely and just stored the list of opaques that may be defined.

fixes #108498
fixes https://github.com/rust-lang/rust/issues/116877

* [x] run crater
  - https://github.com/rust-lang/rust/pull/122077#issuecomment-2013293931

compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs

@@ -68,7 +68,6 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
             &mut orig_values,
             QueryInput {
                 goal,
-                anchor: self.infcx.defining_use_anchor,
                 predefined_opaques_in_body: self
                     .tcx()
                     .mk_predefined_opaques_in_body(PredefinedOpaquesData { opaque_types }),

compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs

@@ -1,5 +1,5 @@
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::DefId;
 use rustc_infer::infer::at::ToTrace;
 use rustc_infer::infer::canonical::CanonicalVarValues;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
@@ -230,7 +230,6 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> {
             .infer_ctxt()
             .intercrate(intercrate)
             .with_next_trait_solver(true)
-            .with_opaque_type_inference(canonical_input.value.anchor)
             .build_with_canonical(DUMMY_SP, &canonical_input);
 
         let mut ecx = EvalCtxt {
@@ -936,8 +935,8 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         }
     }
 
-    pub(super) fn can_define_opaque_ty(&self, def_id: LocalDefId) -> bool {
-        self.infcx.opaque_type_origin(def_id).is_some()
+    pub(super) fn can_define_opaque_ty(&self, def_id: impl Into<DefId>) -> bool {
+        self.infcx.can_define_opaque_ty(def_id)
     }
 
     pub(super) fn insert_hidden_type(

compiler/rustc_trait_selection/src/solve/mod.rs

@@ -316,5 +316,6 @@ fn response_no_constraints_raw<'tcx>(
             external_constraints: tcx.mk_external_constraints(ExternalConstraintsData::default()),
             certainty,
         },
+        defining_opaque_types: Default::default(),
     }
 }

compiler/rustc_trait_selection/src/solve/trait_goals.rs

@@ -155,10 +155,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         if let ty::Alias(ty::Opaque, opaque_ty) = goal.predicate.self_ty().kind() {
             if matches!(goal.param_env.reveal(), Reveal::All)
                 || matches!(ecx.solver_mode(), SolverMode::Coherence)
-                || opaque_ty
-                    .def_id
-                    .as_local()
-                    .is_some_and(|def_id| ecx.can_define_opaque_ty(def_id))
+                || ecx.can_define_opaque_ty(opaque_ty.def_id)
             {
                 return Err(NoSolution);
             }