Auto merge of #140682 - GuillaumeGomez:rollup-6xjf6zn, r=GuillaumeGomez

Rollup of 11 pull requests

Successful merges:

 - #140080 (mir-opt: Use one MirPatch in MatchBranchSimplification)
 - #140115 (mir-opt: execute MatchBranchSimplification after GVN)
 - #140357 (bypass linker configuration and cross target check on `x check`)
 - #140374 (Resolve instance for SymFn in global/naked asm)
 - #140559 (Removing rustc_type_ir in the rustc_infer codebase)
 - #140605 (`fn check_opaque_type_parameter_valid` defer error)
 - #140636 (implement `PanicTracker` to track `t` panics)
 - #140661 (Make `-Zfixed-x18` into a target modifier)
 - #140670 (calculate step duration in a panic-safe way)
 - #140672 (Deeply normalize in the new solver in WF)
 - #140676 (Update books)

r? `@ghost`
`@rustbot` modify labels: rollup

36 files changed, 192 insertions, 132 deletions

diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index 550c57338d3..25cbd579ea1 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -267,13 +267,13 @@ impl<'tcx> InferCtxt<'tcx> {
             return Ty::new_error(self.tcx, e);
         }
 
-        if let Err(guar) = check_opaque_type_parameter_valid(
+        if let Err(err) = check_opaque_type_parameter_valid(
             self,
             opaque_type_key,
             instantiated_ty.span,
             DefiningScopeKind::MirBorrowck,
         ) {
-            return Ty::new_error(self.tcx, guar);
+            return Ty::new_error(self.tcx, err.report(self));
         }
 
         let definition_ty = instantiated_ty
diff --git a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
index d3f47ad7263..e866b896255 100644
--- a/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/intrinsics/mod.rs
@@ -1282,7 +1282,7 @@ fn codegen_regular_intrinsic_call<'tcx>(
                     intrinsic.name,
                 );
             }
-            return Err(Instance::new(instance.def_id(), instance.args));
+            return Err(Instance::new_raw(instance.def_id(), instance.args));
         }
     }
 
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
index d22f4229e23..2ed5ec4381e 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
@@ -399,7 +399,7 @@ impl<'a, 'gcc, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'a, 'gcc, 'tc
             }
 
             // Fall back to default body
-            _ => return Err(Instance::new(instance.def_id(), instance.args)),
+            _ => return Err(Instance::new_raw(instance.def_id(), instance.args)),
         };
 
         if !fn_abi.ret.is_ignore() {
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/unused.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/unused.rs
index 68f60f169b5..fe3a7a1580b 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/unused.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/unused.rs
@@ -157,7 +157,7 @@ fn make_dummy_instance<'tcx>(tcx: TyCtxt<'tcx>, local_def_id: LocalDefId) -> ty:
     let def_id = local_def_id.to_def_id();
 
     // Make a dummy instance that fills in all generics with placeholders.
-    ty::Instance::new(
+    ty::Instance::new_raw(
         def_id,
         ty::GenericArgs::for_item(tcx, def_id, |param, _| {
             if let ty::GenericParamDefKind::Lifetime = param.kind {
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index ffeab59b05c..bfaad8f2f1e 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -613,7 +613,7 @@ impl<'ll, 'tcx> IntrinsicCallBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
             _ => {
                 debug!("unknown intrinsic '{}' -- falling back to default body", name);
                 // Call the fallback body instead of generating the intrinsic code
-                return Err(ty::Instance::new(instance.def_id(), instance.args));
+                return Err(ty::Instance::new_raw(instance.def_id(), instance.args));
             }
         };
 
diff --git a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
index 1bfdbc0b620..5f0a0cf922a 100644
--- a/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
+++ b/compiler/rustc_codegen_ssa/src/back/symbol_export.rs
@@ -612,7 +612,7 @@ pub(crate) fn symbol_name_for_instance_in_crate<'tcx>(
         ExportedSymbol::Generic(def_id, args) => {
             rustc_symbol_mangling::symbol_name_for_instance_in_crate(
                 tcx,
-                Instance::new(def_id, args),
+                Instance::new_raw(def_id, args),
                 instantiating_crate,
             )
         }
@@ -660,7 +660,7 @@ fn calling_convention_for_symbol<'tcx>(
             None
         }
         ExportedSymbol::NonGeneric(def_id) => Some(Instance::mono(tcx, def_id)),
-        ExportedSymbol::Generic(def_id, args) => Some(Instance::new(def_id, args)),
+        ExportedSymbol::Generic(def_id, args) => Some(Instance::new_raw(def_id, args)),
         // DropGlue always use the Rust calling convention and thus follow the target's default
         // symbol decoration scheme.
         ExportedSymbol::DropGlue(..) => None,
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index 89439e40937..775ab9071e7 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -457,7 +457,13 @@ where
                 rustc_hir::InlineAsmOperand::SymFn { expr } => {
                     let ty = cx.tcx().typeck(item_id.owner_id).expr_ty(expr);
                     let instance = match ty.kind() {
-                        &ty::FnDef(def_id, args) => Instance::new(def_id, args),
+                        &ty::FnDef(def_id, args) => Instance::expect_resolve(
+                            cx.tcx(),
+                            ty::TypingEnv::fully_monomorphized(),
+                            def_id,
+                            args,
+                            expr.span,
+                        ),
                         _ => span_bug!(*op_sp, "asm sym is not a function"),
                     };
 
diff --git a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
index 0301ef437c0..d2a687359e0 100644
--- a/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/naked_asm.rs
@@ -95,7 +95,9 @@ fn inline_to_global_operand<'a, 'tcx, Cx: LayoutOf<'tcx, LayoutOfResult = TyAndL
             );
 
             let instance = match mono_type.kind() {
-                &ty::FnDef(def_id, args) => Instance::new(def_id, args),
+                &ty::FnDef(def_id, args) => {
+                    Instance::expect_resolve(cx.tcx(), cx.typing_env(), def_id, args, value.span)
+                }
                 _ => bug!("asm sym is not a function"),
             };
 
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index fa36fe79716..2ec14b2f018 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -76,6 +76,36 @@ impl<'tcx> WfCheckingCtxt<'_, 'tcx> {
         )
     }
 
+    /// Convenience function to *deeply* normalize during wfcheck. In the old solver,
+    /// this just dispatches to [`WfCheckingCtxt::normalize`], but in the new solver
+    /// this calls `deeply_normalize` and reports errors if they are encountered.
+    ///
+    /// This function should be called in favor of `normalize` in cases where we will
+    /// then check the well-formedness of the type, since we only use the normalized
+    /// signature types for implied bounds when checking regions.
+    // FIXME(-Znext-solver): This should be removed when we compute implied outlives
+    // bounds using the unnormalized signature of the function we're checking.
+    fn deeply_normalize<T>(&self, span: Span, loc: Option<WellFormedLoc>, value: T) -> T
+    where
+        T: TypeFoldable<TyCtxt<'tcx>>,
+    {
+        if self.infcx.next_trait_solver() {
+            match self.ocx.deeply_normalize(
+                &ObligationCause::new(span, self.body_def_id, ObligationCauseCode::WellFormed(loc)),
+                self.param_env,
+                value.clone(),
+            ) {
+                Ok(value) => value,
+                Err(errors) => {
+                    self.infcx.err_ctxt().report_fulfillment_errors(errors);
+                    value
+                }
+            }
+        } else {
+            self.normalize(span, loc, value)
+        }
+    }
+
     fn register_wf_obligation(&self, span: Span, loc: Option<WellFormedLoc>, term: ty::Term<'tcx>) {
         let cause = traits::ObligationCause::new(
             span,
@@ -297,7 +327,8 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) -> Result<()
         {
             let res = enter_wf_checking_ctxt(tcx, item.span, def_id, |wfcx| {
                 let ty = tcx.type_of(def_id).instantiate_identity();
-                let item_ty = wfcx.normalize(hir_ty.span, Some(WellFormedLoc::Ty(def_id)), ty);
+                let item_ty =
+                    wfcx.deeply_normalize(hir_ty.span, Some(WellFormedLoc::Ty(def_id)), ty);
                 wfcx.register_wf_obligation(
                     hir_ty.span,
                     Some(WellFormedLoc::Ty(def_id)),
@@ -1073,7 +1104,7 @@ fn check_associated_item(
         match item.kind {
             ty::AssocKind::Const { .. } => {
                 let ty = tcx.type_of(item.def_id).instantiate_identity();
-                let ty = wfcx.normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
+                let ty = wfcx.deeply_normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
                 wfcx.register_wf_obligation(span, loc, ty.into());
                 check_sized_if_body(
                     wfcx,
@@ -1102,7 +1133,7 @@ fn check_associated_item(
                 }
                 if item.defaultness(tcx).has_value() {
                     let ty = tcx.type_of(item.def_id).instantiate_identity();
-                    let ty = wfcx.normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
+                    let ty = wfcx.deeply_normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
                     wfcx.register_wf_obligation(span, loc, ty.into());
                 }
                 Ok(())
@@ -1149,7 +1180,7 @@ fn check_type_defn<'tcx>(
                 let field_id = field.did.expect_local();
                 let hir::FieldDef { ty: hir_ty, .. } =
                     tcx.hir_node_by_def_id(field_id).expect_field();
-                let ty = wfcx.normalize(
+                let ty = wfcx.deeply_normalize(
                     hir_ty.span,
                     None,
                     tcx.type_of(field.did).instantiate_identity(),
@@ -1310,7 +1341,7 @@ fn check_item_type(
 
     enter_wf_checking_ctxt(tcx, ty_span, item_id, |wfcx| {
         let ty = tcx.type_of(item_id).instantiate_identity();
-        let item_ty = wfcx.normalize(ty_span, Some(WellFormedLoc::Ty(item_id)), ty);
+        let item_ty = wfcx.deeply_normalize(ty_span, Some(WellFormedLoc::Ty(item_id)), ty);
 
         let forbid_unsized = match unsized_handling {
             UnsizedHandling::Forbid => true,
@@ -1375,7 +1406,7 @@ fn check_impl<'tcx>(
                 // other `Foo` impls are incoherent.
                 tcx.ensure_ok().coherent_trait(trait_ref.def_id)?;
                 let trait_span = hir_trait_ref.path.span;
-                let trait_ref = wfcx.normalize(
+                let trait_ref = wfcx.deeply_normalize(
                     trait_span,
                     Some(WellFormedLoc::Ty(item.hir_id().expect_owner().def_id)),
                     trait_ref,
@@ -1435,7 +1466,7 @@ fn check_impl<'tcx>(
             }
             None => {
                 let self_ty = tcx.type_of(item.owner_id).instantiate_identity();
-                let self_ty = wfcx.normalize(
+                let self_ty = wfcx.deeply_normalize(
                     item.span,
                     Some(WellFormedLoc::Ty(item.hir_id().expect_owner().def_id)),
                     self_ty,
@@ -1640,7 +1671,7 @@ fn check_fn_or_method<'tcx>(
 
     sig.inputs_and_output =
         tcx.mk_type_list_from_iter(sig.inputs_and_output.iter().enumerate().map(|(idx, ty)| {
-            wfcx.normalize(
+            wfcx.deeply_normalize(
                 arg_span(idx),
                 Some(WellFormedLoc::Param {
                     function: def_id,
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 309b8f2c761..91dde13be55 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -216,7 +216,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
                 check::maybe_check_static_with_link_section(tcx, item_def_id);
             }
             DefKind::Const if tcx.generics_of(item_def_id).is_empty() => {
-                let instance = ty::Instance::new(item_def_id.into(), ty::GenericArgs::empty());
+                let instance = ty::Instance::new_raw(item_def_id.into(), ty::GenericArgs::empty());
                 let cid = GlobalId { instance, promoted: None };
                 let typing_env = ty::TypingEnv::fully_monomorphized();
                 tcx.ensure_ok().eval_to_const_value_raw(typing_env.as_query_input(cid));
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 4a171a08ef7..8e7ce83044c 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -555,15 +555,16 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
                 }
             }
 
-            if let Err(guar) = check_opaque_type_parameter_valid(
+            if let Err(err) = check_opaque_type_parameter_valid(
                 &self.fcx,
                 opaque_type_key,
                 hidden_type.span,
                 DefiningScopeKind::HirTypeck,
             ) {
-                self.typeck_results
-                    .concrete_opaque_types
-                    .insert(opaque_type_key.def_id, ty::OpaqueHiddenType::new_error(tcx, guar));
+                self.typeck_results.concrete_opaque_types.insert(
+                    opaque_type_key.def_id,
+                    ty::OpaqueHiddenType::new_error(tcx, err.report(self.fcx)),
+                );
             }
 
             let hidden_type = hidden_type.remap_generic_params_to_declaration_params(
diff --git a/compiler/rustc_infer/src/infer/context.rs b/compiler/rustc_infer/src/infer/context.rs
index 75affa13977..22d7ce79bb4 100644
--- a/compiler/rustc_infer/src/infer/context.rs
+++ b/compiler/rustc_infer/src/infer/context.rs
@@ -121,19 +121,19 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         self.enter_forall(value, f)
     }
 
-    fn equate_ty_vids_raw(&self, a: rustc_type_ir::TyVid, b: rustc_type_ir::TyVid) {
+    fn equate_ty_vids_raw(&self, a: ty::TyVid, b: ty::TyVid) {
         self.inner.borrow_mut().type_variables().equate(a, b);
     }
 
-    fn equate_int_vids_raw(&self, a: rustc_type_ir::IntVid, b: rustc_type_ir::IntVid) {
+    fn equate_int_vids_raw(&self, a: ty::IntVid, b: ty::IntVid) {
         self.inner.borrow_mut().int_unification_table().union(a, b);
     }
 
-    fn equate_float_vids_raw(&self, a: rustc_type_ir::FloatVid, b: rustc_type_ir::FloatVid) {
+    fn equate_float_vids_raw(&self, a: ty::FloatVid, b: ty::FloatVid) {
         self.inner.borrow_mut().float_unification_table().union(a, b);
     }
 
-    fn equate_const_vids_raw(&self, a: rustc_type_ir::ConstVid, b: rustc_type_ir::ConstVid) {
+    fn equate_const_vids_raw(&self, a: ty::ConstVid, b: ty::ConstVid) {
         self.inner.borrow_mut().const_unification_table().union(a, b);
     }
 
@@ -141,8 +141,8 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         &self,
         relation: &mut R,
         target_is_expected: bool,
-        target_vid: rustc_type_ir::TyVid,
-        instantiation_variance: rustc_type_ir::Variance,
+        target_vid: ty::TyVid,
+        instantiation_variance: ty::Variance,
         source_ty: Ty<'tcx>,
     ) -> RelateResult<'tcx, ()> {
         self.instantiate_ty_var(
@@ -154,19 +154,11 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         )
     }
 
-    fn instantiate_int_var_raw(
-        &self,
-        vid: rustc_type_ir::IntVid,
-        value: rustc_type_ir::IntVarValue,
-    ) {
+    fn instantiate_int_var_raw(&self, vid: ty::IntVid, value: ty::IntVarValue) {
         self.inner.borrow_mut().int_unification_table().union_value(vid, value);
     }
 
-    fn instantiate_float_var_raw(
-        &self,
-        vid: rustc_type_ir::FloatVid,
-        value: rustc_type_ir::FloatVarValue,
-    ) {
+    fn instantiate_float_var_raw(&self, vid: ty::FloatVid, value: ty::FloatVarValue) {
         self.inner.borrow_mut().float_unification_table().union_value(vid, value);
     }
 
@@ -174,7 +166,7 @@ impl<'tcx> rustc_type_ir::InferCtxtLike for InferCtxt<'tcx> {
         &self,
         relation: &mut R,
         target_is_expected: bool,
-        target_vid: rustc_type_ir::ConstVid,
+        target_vid: ty::ConstVid,
         source_ct: ty::Const<'tcx>,
     ) -> RelateResult<'tcx, ()> {
         self.instantiate_const_var(relation, target_is_expected, target_vid, source_ct)
diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs
index a89cef50c9b..8dde99c45cf 100644
--- a/compiler/rustc_infer/src/infer/outlives/obligations.rs
+++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs
@@ -63,11 +63,11 @@ use rustc_data_structures::undo_log::UndoLogs;
 use rustc_middle::bug;
 use rustc_middle::mir::ConstraintCategory;
 use rustc_middle::traits::query::NoSolution;
+use rustc_middle::ty::outlives::{Component, push_outlives_components};
 use rustc_middle::ty::{
     self, GenericArgKind, GenericArgsRef, PolyTypeOutlivesPredicate, Region, Ty, TyCtxt,
     TypeFoldable as _, TypeVisitableExt,
 };
-use rustc_type_ir::outlives::{Component, push_outlives_components};
 use smallvec::smallvec;
 use tracing::{debug, instrument};
 
diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs
index c14c288c6e4..69feecfe30a 100644
--- a/compiler/rustc_infer/src/infer/outlives/verify.rs
+++ b/compiler/rustc_infer/src/infer/outlives/verify.rs
@@ -1,7 +1,7 @@
 use std::assert_matches::assert_matches;
 
+use rustc_middle::ty::outlives::{Component, compute_alias_components_recursive};
 use rustc_middle::ty::{self, OutlivesPredicate, Ty, TyCtxt};
-use rustc_type_ir::outlives::{Component, compute_alias_components_recursive};
 use smallvec::smallvec;
 use tracing::{debug, instrument, trace};
 
diff --git a/compiler/rustc_infer/src/infer/relate/mod.rs b/compiler/rustc_infer/src/infer/relate/mod.rs
index e6d1003cab6..6d25dfeb859 100644
--- a/compiler/rustc_infer/src/infer/relate/mod.rs
+++ b/compiler/rustc_infer/src/infer/relate/mod.rs
@@ -2,9 +2,8 @@
 //! (except for some relations used for diagnostics and heuristics in the compiler).
 //! As well as the implementation of `Relate` for interned things (`Ty`/`Const`/etc).
 
-pub use rustc_middle::ty::relate::RelateResult;
-pub use rustc_type_ir::relate::combine::PredicateEmittingRelation;
-pub use rustc_type_ir::relate::*;
+pub use rustc_middle::ty::relate::combine::PredicateEmittingRelation;
+pub use rustc_middle::ty::relate::{RelateResult, *};
 
 mod generalize;
 mod higher_ranked;
diff --git a/compiler/rustc_infer/src/infer/relate/type_relating.rs b/compiler/rustc_infer/src/infer/relate/type_relating.rs
index 009271a8378..04ff776594e 100644
--- a/compiler/rustc_infer/src/infer/relate/type_relating.rs
+++ b/compiler/rustc_infer/src/infer/relate/type_relating.rs
@@ -3,9 +3,8 @@ use rustc_middle::ty::relate::combine::{super_combine_consts, super_combine_tys}
 use rustc_middle::ty::relate::{
     Relate, RelateResult, TypeRelation, relate_args_invariantly, relate_args_with_variances,
 };
-use rustc_middle::ty::{self, Ty, TyCtxt, TyVar};
+use rustc_middle::ty::{self, DelayedSet, Ty, TyCtxt, TyVar};
 use rustc_span::Span;
-use rustc_type_ir::data_structures::DelayedSet;
 use tracing::{debug, instrument};
 
 use crate::infer::BoundRegionConversionTime::HigherRankedType;
diff --git a/compiler/rustc_infer/src/infer/resolve.rs b/compiler/rustc_infer/src/infer/resolve.rs
index 245f1a4ac5e..4b0ace8c554 100644
--- a/compiler/rustc_infer/src/infer/resolve.rs
+++ b/compiler/rustc_infer/src/infer/resolve.rs
@@ -1,9 +1,8 @@
 use rustc_middle::bug;
 use rustc_middle::ty::{
-    self, Const, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeFolder,
+    self, Const, DelayedMap, FallibleTypeFolder, InferConst, Ty, TyCtxt, TypeFoldable, TypeFolder,
     TypeSuperFoldable, TypeVisitableExt,
 };
-use rustc_type_ir::data_structures::DelayedMap;
 
 use super::{FixupError, FixupResult, InferCtxt};
 
diff --git a/compiler/rustc_infer/src/infer/snapshot/fudge.rs b/compiler/rustc_infer/src/infer/snapshot/fudge.rs
index 39c8c40ea7d..e210479581b 100644
--- a/compiler/rustc_infer/src/infer/snapshot/fudge.rs
+++ b/compiler/rustc_infer/src/infer/snapshot/fudge.rs
@@ -3,9 +3,8 @@ use std::ops::Range;
 use rustc_data_structures::{snapshot_vec as sv, unify as ut};
 use rustc_middle::ty::{
     self, ConstVid, FloatVid, IntVid, RegionVid, Ty, TyCtxt, TyVid, TypeFoldable, TypeFolder,
-    TypeSuperFoldable,
+    TypeSuperFoldable, TypeVisitableExt,
 };
-use rustc_type_ir::TypeVisitableExt;
 use tracing::instrument;
 use ut::UnifyKey;
 
diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs
index 66ed49fe326..6461fbe0d33 100644
--- a/compiler/rustc_infer/src/traits/util.rs
+++ b/compiler/rustc_infer/src/traits/util.rs
@@ -1,7 +1,7 @@
 use rustc_data_structures::fx::FxHashSet;
+pub use rustc_middle::ty::elaborate::*;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::{Ident, Span};
-pub use rustc_type_ir::elaborate::*;
 
 use crate::traits::{self, Obligation, ObligationCauseCode, PredicateObligation};
 
diff --git a/compiler/rustc_lint/src/foreign_modules.rs b/compiler/rustc_lint/src/foreign_modules.rs
index 0494c78a7a9..d0668794198 100644
--- a/compiler/rustc_lint/src/foreign_modules.rs
+++ b/compiler/rustc_lint/src/foreign_modules.rs
@@ -104,7 +104,7 @@ impl ClashingExternDeclarations {
     /// for the item, return its HirId without updating the set.
     fn insert(&mut self, tcx: TyCtxt<'_>, fi: hir::ForeignItemId) -> Option<hir::OwnerId> {
         let did = fi.owner_id.to_def_id();
-        let instance = Instance::new(did, ty::List::identity_for_item(tcx, did));
+        let instance = Instance::new_raw(did, ty::List::identity_for_item(tcx, did));
         let name = Symbol::intern(tcx.symbol_name(instance).name);
         if let Some(&existing_id) = self.seen_decls.get(&name) {
             // Avoid updating the map with the new entry when we do find a collision. We want to
diff --git a/compiler/rustc_middle/src/middle/exported_symbols.rs b/compiler/rustc_middle/src/middle/exported_symbols.rs
index 3c62017072e..1d67d0fe3bb 100644
--- a/compiler/rustc_middle/src/middle/exported_symbols.rs
+++ b/compiler/rustc_middle/src/middle/exported_symbols.rs
@@ -56,7 +56,7 @@ impl<'tcx> ExportedSymbol<'tcx> {
         match *self {
             ExportedSymbol::NonGeneric(def_id) => tcx.symbol_name(ty::Instance::mono(tcx, def_id)),
             ExportedSymbol::Generic(def_id, args) => {
-                tcx.symbol_name(ty::Instance::new(def_id, args))
+                tcx.symbol_name(ty::Instance::new_raw(def_id, args))
             }
             ExportedSymbol::DropGlue(ty) => {
                 tcx.symbol_name(ty::Instance::resolve_drop_in_place(tcx, ty))
diff --git a/compiler/rustc_middle/src/mir/interpret/queries.rs b/compiler/rustc_middle/src/mir/interpret/queries.rs
index e5d1dda3aa0..4a5c42c721c 100644
--- a/compiler/rustc_middle/src/mir/interpret/queries.rs
+++ b/compiler/rustc_middle/src/mir/interpret/queries.rs
@@ -23,7 +23,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self, def_id);
-        let instance = ty::Instance::new(def_id, args);
+        let instance = ty::Instance::new_raw(def_id, args);
         let cid = GlobalId { instance, promoted: None };
         let typing_env = ty::TypingEnv::post_analysis(self, def_id);
         self.const_eval_global_id(typing_env, cid, DUMMY_SP)
@@ -39,7 +39,7 @@ impl<'tcx> TyCtxt<'tcx> {
         // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self, def_id);
-        let instance = ty::Instance::new(def_id, args);
+        let instance = ty::Instance::new_raw(def_id, args);
         let cid = GlobalId { instance, promoted: None };
         let typing_env = ty::TypingEnv::post_analysis(self, def_id);
         let inputs = self.erase_regions(typing_env.as_query_input(cid));
@@ -209,7 +209,7 @@ impl<'tcx> TyCtxtEnsureOk<'tcx> {
         // into `const_eval` which will return `ErrorHandled::TooGeneric` if any of them are
         // encountered.
         let args = GenericArgs::identity_for_item(self.tcx, def_id);
-        let instance = ty::Instance::new(def_id, self.tcx.erase_regions(args));
+        let instance = ty::Instance::new_raw(def_id, self.tcx.erase_regions(args));
         let cid = GlobalId { instance, promoted: None };
         let typing_env = ty::TypingEnv::post_analysis(self.tcx, def_id);
         // Const-eval shouldn't depend on lifetimes at all, so we can erase them, which should
diff --git a/compiler/rustc_middle/src/mir/mono.rs b/compiler/rustc_middle/src/mir/mono.rs
index 6b413a7383a..7243f87ee63 100644
--- a/compiler/rustc_middle/src/mir/mono.rs
+++ b/compiler/rustc_middle/src/mir/mono.rs
@@ -318,7 +318,7 @@ impl<'tcx> fmt::Display for MonoItem<'tcx> {
         match *self {
             MonoItem::Fn(instance) => write!(f, "fn {instance}"),
             MonoItem::Static(def_id) => {
-                write!(f, "static {}", Instance::new(def_id, GenericArgs::empty()))
+                write!(f, "static {}", Instance::new_raw(def_id, GenericArgs::empty()))
             }
             MonoItem::GlobalAsm(..) => write!(f, "global_asm"),
         }
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 6af9d4aae30..4981233cebe 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -2481,7 +2481,7 @@ rustc_queries! {
     query resolve_instance_raw(
         key: ty::PseudoCanonicalInput<'tcx, (DefId, GenericArgsRef<'tcx>)>
     ) -> Result<Option<ty::Instance<'tcx>>, ErrorGuaranteed> {
-        desc { "resolving instance `{}`", ty::Instance::new(key.value.0, key.value.1) }
+        desc { "resolving instance `{}`", ty::Instance::new_raw(key.value.0, key.value.1) }
     }
 
     query reveal_opaque_types_in_bounds(key: ty::Clauses<'tcx>) -> ty::Clauses<'tcx> {
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index d660e7d0d60..0d99a1b5149 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -491,7 +491,15 @@ fn resolve_async_drop_poll<'tcx>(mut cor_ty: Ty<'tcx>) -> Instance<'tcx> {
 }
 
 impl<'tcx> Instance<'tcx> {
-    pub fn new(def_id: DefId, args: GenericArgsRef<'tcx>) -> Instance<'tcx> {
+    /// Creates a new [`InstanceKind::Item`] from the `def_id` and `args`.
+    ///
+    /// Note that this item corresponds to the body of `def_id` directly, which
+    /// likely does not make sense for trait items which need to be resolved to an
+    /// implementation, and which may not even have a body themselves. Usages of
+    /// this function should probably use [`Instance::expect_resolve`], or if run
+    /// in a polymorphic environment or within a lint (that may encounter ambiguity)
+    /// [`Instance::try_resolve`] instead.
+    pub fn new_raw(def_id: DefId, args: GenericArgsRef<'tcx>) -> Instance<'tcx> {
         assert!(
             !args.has_escaping_bound_vars(),
             "args of instance {def_id:?} has escaping bound vars: {args:?}"
@@ -510,7 +518,7 @@ impl<'tcx> Instance<'tcx> {
             }
         });
 
-        Instance::new(def_id, args)
+        Instance::new_raw(def_id, args)
     }
 
     #[inline]
@@ -603,7 +611,7 @@ impl<'tcx> Instance<'tcx> {
                 let type_length = type_length(args);
                 if !tcx.type_length_limit().value_within_limit(type_length) {
                     let (shrunk, written_to_path) =
-                        shrunk_instance_name(tcx, Instance::new(def_id, args));
+                        shrunk_instance_name(tcx, Instance::new_raw(def_id, args));
                     let mut path = PathBuf::new();
                     let was_written = if let Some(path2) = written_to_path {
                         path = path2;
@@ -773,7 +781,7 @@ impl<'tcx> Instance<'tcx> {
 
         match needs_fn_once_adapter_shim(actual_kind, requested_kind) {
             Ok(true) => Instance::fn_once_adapter_instance(tcx, def_id, args),
-            _ => Instance::new(def_id, args),
+            _ => Instance::new_raw(def_id, args),
         }
     }
 
@@ -899,7 +907,7 @@ impl<'tcx> Instance<'tcx> {
             // This is important for `Iterator`'s combinators, but also useful for
             // adding future default methods to `Future`, for instance.
             debug_assert!(tcx.defaultness(trait_item_id).has_value());
-            Some(Instance::new(trait_item_id, rcvr_args))
+            Some(Instance::new_raw(trait_item_id, rcvr_args))
         }
     }
 
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index b8da97c42d4..f1ef98c2097 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -51,9 +51,17 @@ use rustc_session::lint::LintBuffer;
 pub use rustc_session::lint::RegisteredTools;
 use rustc_span::hygiene::MacroKind;
 use rustc_span::{DUMMY_SP, ExpnId, ExpnKind, Ident, Span, Symbol, kw, sym};
-pub use rustc_type_ir::data_structures::DelayedSet;
+pub use rustc_type_ir::data_structures::{DelayedMap, DelayedSet};
+#[allow(
+    hidden_glob_reexports,
+    rustc::usage_of_type_ir_inherent,
+    rustc::non_glob_import_of_type_ir_inherent
+)]
+use rustc_type_ir::inherent;
 pub use rustc_type_ir::relate::VarianceDiagInfo;
 pub use rustc_type_ir::*;
+#[allow(hidden_glob_reexports, unused_imports)]
+use rustc_type_ir::{InferCtxtLike, Interner};
 use tracing::{debug, instrument};
 pub use vtable::*;
 use {rustc_ast as ast, rustc_attr_data_structures as attr, rustc_hir as hir};
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 24f4c11a66d..dc0eacd3613 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -701,8 +701,6 @@ pub(crate) fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'
             // Now, we need to shrink the generated MIR.
             &ref_prop::ReferencePropagation,
             &sroa::ScalarReplacementOfAggregates,
-            &match_branches::MatchBranchSimplification,
-            // inst combine is after MatchBranchSimplification to clean up Ne(_1, false)
             &multiple_return_terminators::MultipleReturnTerminators,
             // After simplifycfg, it allows us to discover new opportunities for peephole
             // optimizations.
@@ -711,6 +709,7 @@ pub(crate) fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'
             &dead_store_elimination::DeadStoreElimination::Initial,
             &gvn::GVN,
             &simplify::SimplifyLocals::AfterGVN,
+            &match_branches::MatchBranchSimplification,
             &dataflow_const_prop::DataflowConstProp,
             &single_use_consts::SingleUseConsts,
             &o1(simplify_branches::SimplifyConstCondition::AfterConstProp),
diff --git a/compiler/rustc_mir_transform/src/match_branches.rs b/compiler/rustc_mir_transform/src/match_branches.rs
index b37241185c9..8c0c3096899 100644
--- a/compiler/rustc_mir_transform/src/match_branches.rs
+++ b/compiler/rustc_mir_transform/src/match_branches.rs
@@ -19,30 +19,32 @@ impl<'tcx> crate::MirPass<'tcx> for MatchBranchSimplification {
 
     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
         let typing_env = body.typing_env(tcx);
-        let mut should_cleanup = false;
-        for bb_idx in body.basic_blocks.indices() {
-            match &body.basic_blocks[bb_idx].terminator().kind {
+        let mut apply_patch = false;
+        let mut patch = MirPatch::new(body);
+        for (bb, bb_data) in body.basic_blocks.iter_enumerated() {
+            match &bb_data.terminator().kind {
                 TerminatorKind::SwitchInt {
                     discr: Operand::Copy(_) | Operand::Move(_),
                     targets,
                     ..
                     // We require that the possible target blocks don't contain this block.
-                } if !targets.all_targets().contains(&bb_idx) => {}
+                } if !targets.all_targets().contains(&bb) => {}
                 // Only optimize switch int statements
                 _ => continue,
             };
 
-            if SimplifyToIf.simplify(tcx, body, bb_idx, typing_env).is_some() {
-                should_cleanup = true;
+            if SimplifyToIf.simplify(tcx, body, &mut patch, bb, typing_env).is_some() {
+                apply_patch = true;
                 continue;
             }
-            if SimplifyToExp::default().simplify(tcx, body, bb_idx, typing_env).is_some() {
-                should_cleanup = true;
+            if SimplifyToExp::default().simplify(tcx, body, &mut patch, bb, typing_env).is_some() {
+                apply_patch = true;
                 continue;
             }
         }
 
-        if should_cleanup {
+        if apply_patch {
+            patch.apply(body);
             simplify_cfg(tcx, body);
         }
     }
@@ -59,7 +61,8 @@ trait SimplifyMatch<'tcx> {
     fn simplify(
         &mut self,
         tcx: TyCtxt<'tcx>,
-        body: &mut Body<'tcx>,
+        body: &Body<'tcx>,
+        patch: &mut MirPatch<'tcx>,
         switch_bb_idx: BasicBlock,
         typing_env: ty::TypingEnv<'tcx>,
     ) -> Option<()> {
@@ -73,8 +76,6 @@ trait SimplifyMatch<'tcx> {
         let discr_ty = discr.ty(body.local_decls(), tcx);
         self.can_simplify(tcx, targets, typing_env, bbs, discr_ty)?;
 
-        let mut patch = MirPatch::new(body);
-
         // Take ownership of items now that we know we can optimize.
         let discr = discr.clone();
 
@@ -87,19 +88,9 @@ trait SimplifyMatch<'tcx> {
         let parent_end = Location { block: switch_bb_idx, statement_index };
         patch.add_statement(parent_end, StatementKind::StorageLive(discr_local));
         patch.add_assign(parent_end, Place::from(discr_local), Rvalue::Use(discr));
-        self.new_stmts(
-            tcx,
-            targets,
-            typing_env,
-            &mut patch,
-            parent_end,
-            bbs,
-            discr_local,
-            discr_ty,
-        );
+        self.new_stmts(tcx, targets, typing_env, patch, parent_end, bbs, discr_local, discr_ty);
         patch.add_statement(parent_end, StatementKind::StorageDead(discr_local));
         patch.patch_terminator(switch_bb_idx, bbs[first].terminator().kind.clone());
-        patch.apply(body);
         Some(())
     }
 
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 1e3744e19f5..c6a81e60b2b 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -931,7 +931,7 @@ fn visit_instance_use<'tcx>(
             // We explicitly skip this otherwise to ensure we get a linker error
             // if anyone tries to call this intrinsic and the codegen backend did not
             // override the implementation.
-            let instance = ty::Instance::new(instance.def_id(), instance.args);
+            let instance = ty::Instance::new_raw(instance.def_id(), instance.args);
             if tcx.should_codegen_locally(instance) {
                 output.push(create_fn_mono_item(tcx, instance, source));
             }
@@ -1520,7 +1520,7 @@ impl<'v> RootCollector<'_, 'v> {
                         ty::Closure(def_id, args)
                         | ty::Coroutine(def_id, args)
                         | ty::CoroutineClosure(def_id, args) => {
-                            Instance::new(def_id, self.tcx.erase_regions(args))
+                            Instance::new_raw(def_id, self.tcx.erase_regions(args))
                         }
                         _ => unreachable!(),
                     };
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 440e8f808c7..b95ebfbe89f 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -2210,7 +2210,7 @@ options! {
     fewer_names: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "reduce memory use by retaining fewer names within compilation artifacts (LLVM-IR) \
         (default: no)"),
-    fixed_x18: bool = (false, parse_bool, [TRACKED],
+    fixed_x18: bool = (false, parse_bool, [TRACKED TARGET_MODIFIER],
         "make the x18 register reserved on AArch64 (default: no)"),
     flatten_format_args: bool = (true, parse_bool, [TRACKED],
         "flatten nested format_args!() and literals into a simplified format_args!() call \
diff --git a/compiler/rustc_smir/src/rustc_smir/builder.rs b/compiler/rustc_smir/src/rustc_smir/builder.rs
index 64763b71d30..40e6d21c063 100644
--- a/compiler/rustc_smir/src/rustc_smir/builder.rs
+++ b/compiler/rustc_smir/src/rustc_smir/builder.rs
@@ -22,7 +22,7 @@ impl<'tcx> BodyBuilder<'tcx> {
     pub(crate) fn new(tcx: TyCtxt<'tcx>, instance: ty::Instance<'tcx>) -> Self {
         let instance = match instance.def {
             // To get the fallback body of an intrinsic, we need to convert it to an item.
-            ty::InstanceKind::Intrinsic(def_id) => ty::Instance::new(def_id, instance.args),
+            ty::InstanceKind::Intrinsic(def_id) => ty::Instance::new_raw(def_id, instance.args),
             _ => instance,
         };
         BodyBuilder { tcx, instance }
diff --git a/compiler/rustc_symbol_mangling/src/test.rs b/compiler/rustc_symbol_mangling/src/test.rs
index ddeeadff13d..0c6d1495e39 100644
--- a/compiler/rustc_symbol_mangling/src/test.rs
+++ b/compiler/rustc_symbol_mangling/src/test.rs
@@ -56,7 +56,7 @@ impl SymbolNamesTest<'_> {
         // some subset.
         for attr in tcx.get_attrs(def_id, SYMBOL_NAME) {
             let def_id = def_id.to_def_id();
-            let instance = Instance::new(
+            let instance = Instance::new_raw(
                 def_id,
                 tcx.erase_regions(GenericArgs::identity_for_item(tcx, def_id)),
             );
diff --git a/compiler/rustc_trait_selection/Cargo.toml b/compiler/rustc_trait_selection/Cargo.toml
index 1071105522d..e6de2a3978d 100644
--- a/compiler/rustc_trait_selection/Cargo.toml
+++ b/compiler/rustc_trait_selection/Cargo.toml
@@ -20,6 +20,7 @@ rustc_parse_format = { path = "../rustc_parse_format" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_transmute = { path = "../rustc_transmute", features = ["rustc"] }
+rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2"
 tracing = "0.1"
diff --git a/compiler/rustc_trait_selection/src/opaque_types.rs b/compiler/rustc_trait_selection/src/opaque_types.rs
index cce67b066dd..332204a0c5f 100644
--- a/compiler/rustc_trait_selection/src/opaque_types.rs
+++ b/compiler/rustc_trait_selection/src/opaque_types.rs
@@ -13,6 +13,49 @@ use crate::errors::NonGenericOpaqueTypeParam;
 use crate::regions::OutlivesEnvironmentBuildExt;
 use crate::traits::ObligationCtxt;
 
+pub enum InvalidOpaqueTypeArgs<'tcx> {
+    AlreadyReported(ErrorGuaranteed),
+    NotAParam { opaque_type_key: OpaqueTypeKey<'tcx>, param_index: usize, span: Span },
+    DuplicateParam { opaque_type_key: OpaqueTypeKey<'tcx>, param_indices: Vec<usize>, span: Span },
+}
+impl From<ErrorGuaranteed> for InvalidOpaqueTypeArgs<'_> {
+    fn from(guar: ErrorGuaranteed) -> Self {
+        InvalidOpaqueTypeArgs::AlreadyReported(guar)
+    }
+}
+impl<'tcx> InvalidOpaqueTypeArgs<'tcx> {
+    pub fn report(self, infcx: &InferCtxt<'tcx>) -> ErrorGuaranteed {
+        let tcx = infcx.tcx;
+        match self {
+            InvalidOpaqueTypeArgs::AlreadyReported(guar) => guar,
+            InvalidOpaqueTypeArgs::NotAParam { opaque_type_key, param_index, span } => {
+                let opaque_generics = tcx.generics_of(opaque_type_key.def_id);
+                let opaque_param = opaque_generics.param_at(param_index, tcx);
+                let kind = opaque_param.kind.descr();
+                infcx.dcx().emit_err(NonGenericOpaqueTypeParam {
+                    arg: opaque_type_key.args[param_index],
+                    kind,
+                    span,
+                    param_span: tcx.def_span(opaque_param.def_id),
+                })
+            }
+            InvalidOpaqueTypeArgs::DuplicateParam { opaque_type_key, param_indices, span } => {
+                let opaque_generics = tcx.generics_of(opaque_type_key.def_id);
+                let descr = opaque_generics.param_at(param_indices[0], tcx).kind.descr();
+                let spans: Vec<_> = param_indices
+                    .into_iter()
+                    .map(|i| tcx.def_span(opaque_generics.param_at(i, tcx).def_id))
+                    .collect();
+                infcx
+                    .dcx()
+                    .struct_span_err(span, "non-defining opaque type use in defining scope")
+                    .with_span_note(spans, format!("{descr} used multiple times"))
+                    .emit()
+            }
+        }
+    }
+}
+
 /// Opaque type parameter validity check as documented in the [rustc-dev-guide chapter].
 ///
 /// [rustc-dev-guide chapter]:
@@ -22,23 +65,19 @@ pub fn check_opaque_type_parameter_valid<'tcx>(
     opaque_type_key: OpaqueTypeKey<'tcx>,
     span: Span,
     defining_scope_kind: DefiningScopeKind,
-) -> Result<(), ErrorGuaranteed> {
+) -> Result<(), InvalidOpaqueTypeArgs<'tcx>> {
     let tcx = infcx.tcx;
-    let opaque_generics = tcx.generics_of(opaque_type_key.def_id);
     let opaque_env = LazyOpaqueTyEnv::new(tcx, opaque_type_key.def_id);
     let mut seen_params: FxIndexMap<_, Vec<_>> = FxIndexMap::default();
 
     // Avoid duplicate errors in case the opaque has already been malformed in
     // HIR typeck.
     if let DefiningScopeKind::MirBorrowck = defining_scope_kind {
-        if let Err(guar) = infcx
+        infcx
             .tcx
             .type_of_opaque_hir_typeck(opaque_type_key.def_id)
             .instantiate_identity()
-            .error_reported()
-        {
-            return Err(guar);
-        }
+            .error_reported()?;
     }
 
     for (i, arg) in opaque_type_key.iter_captured_args(tcx) {
@@ -64,32 +103,18 @@ pub fn check_opaque_type_parameter_valid<'tcx>(
             }
         } else {
             // Prevent `fn foo() -> Foo<u32>` from being defining.
-            let opaque_param = opaque_generics.param_at(i, tcx);
-            let kind = opaque_param.kind.descr();
-
             opaque_env.param_is_error(i)?;
-
-            return Err(infcx.dcx().emit_err(NonGenericOpaqueTypeParam {
-                arg,
-                kind,
-                span,
-                param_span: tcx.def_span(opaque_param.def_id),
-            }));
+            return Err(InvalidOpaqueTypeArgs::NotAParam { opaque_type_key, param_index: i, span });
         }
     }
 
-    for (_, indices) in seen_params {
-        if indices.len() > 1 {
-            let descr = opaque_generics.param_at(indices[0], tcx).kind.descr();
-            let spans: Vec<_> = indices
-                .into_iter()
-                .map(|i| tcx.def_span(opaque_generics.param_at(i, tcx).def_id))
-                .collect();
-            return Err(infcx
-                .dcx()
-                .struct_span_err(span, "non-defining opaque type use in defining scope")
-                .with_span_note(spans, format!("{descr} used multiple times"))
-                .emit());
+    for (_, param_indices) in seen_params {
+        if param_indices.len() > 1 {
+            return Err(InvalidOpaqueTypeArgs::DuplicateParam {
+                opaque_type_key,
+                param_indices,
+                span,
+            });
         }
     }
 
diff --git a/compiler/rustc_trait_selection/src/solve/delegate.rs b/compiler/rustc_trait_selection/src/solve/delegate.rs
index ef64da13189..908c058aabe 100644
--- a/compiler/rustc_trait_selection/src/solve/delegate.rs
+++ b/compiler/rustc_trait_selection/src/solve/delegate.rs
@@ -156,9 +156,9 @@ impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<
     fn register_hidden_type_in_storage(
         &self,
         opaque_type_key: ty::OpaqueTypeKey<'tcx>,
-        hidden_ty: <Self::Interner as ty::Interner>::Ty,
-        span: <Self::Interner as ty::Interner>::Span,
-    ) -> Option<<Self::Interner as ty::Interner>::Ty> {
+        hidden_ty: <Self::Interner as rustc_type_ir::Interner>::Ty,
+        span: <Self::Interner as rustc_type_ir::Interner>::Span,
+    ) -> Option<<Self::Interner as rustc_type_ir::Interner>::Ty> {
         self.0.register_hidden_type_in_storage(
             opaque_type_key,
             ty::OpaqueHiddenType { span, ty: hidden_ty },
diff --git a/compiler/rustc_ty_utils/src/instance.rs b/compiler/rustc_ty_utils/src/instance.rs
index da83566dad0..166e8f19342 100644
--- a/compiler/rustc_ty_utils/src/instance.rs
+++ b/compiler/rustc_ty_utils/src/instance.rs
@@ -235,7 +235,7 @@ fn resolve_associated_item<'tcx>(
                 tcx.ensure_ok().compare_impl_item(leaf_def_item)?;
             }
 
-            Some(ty::Instance::new(leaf_def.item.def_id, args))
+            Some(ty::Instance::new_raw(leaf_def.item.def_id, args))
         }
         traits::ImplSource::Builtin(BuiltinImplSource::Object(_), _) => {
             let trait_ref = ty::TraitRef::from_method(tcx, trait_id, rcvr_args);
@@ -280,7 +280,7 @@ fn resolve_associated_item<'tcx>(
 
                     // Use the default `fn clone_from` from `trait Clone`.
                     let args = tcx.erase_regions(rcvr_args);
-                    Some(ty::Instance::new(trait_item_id, args))
+                    Some(ty::Instance::new_raw(trait_item_id, args))
                 }
             } else if tcx.is_lang_item(trait_ref.def_id, LangItem::FnPtrTrait) {
                 if tcx.is_lang_item(trait_item_id, LangItem::FnPtrAddr) {
@@ -329,7 +329,7 @@ fn resolve_associated_item<'tcx>(
                         // sync with the built-in trait implementations (since all of the
                         // implementations return `FnOnce::Output`).
                         if ty::ClosureKind::FnOnce == args.as_coroutine_closure().kind() {
-                            Some(Instance::new(coroutine_closure_def_id, args))
+                            Some(Instance::new_raw(coroutine_closure_def_id, args))
                         } else {
                             Some(Instance {
                                 def: ty::InstanceKind::ConstructCoroutineInClosureShim {
@@ -362,7 +362,7 @@ fn resolve_associated_item<'tcx>(
                                 args,
                             })
                         } else {
-                            Some(Instance::new(coroutine_closure_def_id, args))
+                            Some(Instance::new_raw(coroutine_closure_def_id, args))
                         }
                     }
                     ty::Closure(closure_def_id, args) => {
@@ -381,7 +381,7 @@ fn resolve_associated_item<'tcx>(
                 let name = tcx.item_name(trait_item_id);
                 assert_eq!(name, sym::transmute);
                 let args = tcx.erase_regions(rcvr_args);
-                Some(ty::Instance::new(trait_item_id, args))
+                Some(ty::Instance::new_raw(trait_item_id, args))
             } else {
                 Instance::try_resolve_item_for_coroutine(tcx, trait_item_id, trait_id, rcvr_args)
             }