Revert "Use DeepRejectCtxt in assemble_inherent_candidates_from_param"

This reverts commit ad59f0b6e6e5c45ea64064758a88e8521259bfcf.

4 files changed, 12 insertions, 58 deletions

diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index aae870f7ee3..924779f8dc0 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -1,7 +1,6 @@
 // tidy-alphabetical-start
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
-#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 1f3969bd93c..fbbd6e9957f 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -1,4 +1,3 @@
-use std::assert_matches::debug_assert_matches;
 use std::cell::{Cell, RefCell};
 use std::cmp::max;
 use std::ops::Deref;
@@ -16,7 +15,7 @@ use rustc_infer::infer::{BoundRegionConversionTime, DefineOpaqueTypes, InferOk,
 use rustc_infer::traits::ObligationCauseCode;
 use rustc_middle::middle::stability;
 use rustc_middle::ty::elaborate::supertrait_def_ids;
-use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams, simplify_type};
+use rustc_middle::ty::fast_reject::{TreatParams, simplify_type};
 use rustc_middle::ty::{
     self, AssocItem, AssocItemContainer, GenericArgs, GenericArgsRef, GenericParamDefKind,
     ParamEnvAnd, Ty, TyCtxt, TypeVisitableExt, Upcast,
@@ -803,8 +802,8 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                     );
                 }
             }
-            ty::Param(_) => {
-                self.assemble_inherent_candidates_from_param(raw_self_ty);
+            ty::Param(p) => {
+                self.assemble_inherent_candidates_from_param(p);
             }
             ty::Bool
             | ty::Char
@@ -905,16 +904,18 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
     }
 
     #[instrument(level = "debug", skip(self))]
-    fn assemble_inherent_candidates_from_param(&mut self, param_ty: Ty<'tcx>) {
-        debug_assert_matches!(param_ty.kind(), ty::Param(_));
-
-        let tcx = self.tcx;
+    fn assemble_inherent_candidates_from_param(&mut self, param_ty: ty::ParamTy) {
         let bounds = self.param_env.caller_bounds().iter().filter_map(|predicate| {
             let bound_predicate = predicate.kind();
             match bound_predicate.skip_binder() {
-                ty::ClauseKind::Trait(trait_predicate) => DeepRejectCtxt::relate_rigid_rigid(tcx)
-                    .types_may_unify(param_ty, trait_predicate.trait_ref.self_ty())
-                    .then(|| bound_predicate.rebind(trait_predicate.trait_ref)),
+                ty::ClauseKind::Trait(trait_predicate) => {
+                    match *trait_predicate.trait_ref.self_ty().kind() {
+                        ty::Param(p) if p == param_ty => {
+                            Some(bound_predicate.rebind(trait_predicate.trait_ref))
+                        }
+                        _ => None,
+                    }
+                }
                 ty::ClauseKind::RegionOutlives(_)
                 | ty::ClauseKind::TypeOutlives(_)
                 | ty::ClauseKind::Projection(_)
diff --git a/tests/ui/traits/next-solver/method/param-method-from-unnormalized-param-env-2.rs b/tests/ui/traits/next-solver/method/param-method-from-unnormalized-param-env-2.rs
deleted file mode 100644
index ffb99d6d638..00000000000
--- a/tests/ui/traits/next-solver/method/param-method-from-unnormalized-param-env-2.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-//@ check-pass
-//@ revisions: current next
-//@ ignore-compare-mode-next-solver (explicit revisions)
-//@[next] compile-flags: -Znext-solver
-
-// Regression test for <https://github.com/rust-lang/trait-system-refactor-initiative/issues/214>.
-// See comment below.
-
-trait A {
-    fn hello(&self) {}
-}
-
-trait B {
-    fn hello(&self) {}
-}
-
-impl<T> A for T {}
-impl<T> B for T {}
-
-fn test<F, R>(q: F::Item)
-where
-    F: Iterator<Item = R>,
-    // We want to prefer `A` for `R.hello()`
-    F::Item: A,
-{
-    q.hello();
-}
-
-fn main() {}
diff --git a/tests/ui/traits/next-solver/method/param-method-from-unnormalized-param-env.rs b/tests/ui/traits/next-solver/method/param-method-from-unnormalized-param-env.rs
deleted file mode 100644
index dde4f745879..00000000000
--- a/tests/ui/traits/next-solver/method/param-method-from-unnormalized-param-env.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-//@ check-pass
-//@ compile-flags: -Znext-solver
-
-// Regression test for <https://github.com/rust-lang/trait-system-refactor-initiative/issues/214>.
-
-fn execute<K, F, R>(q: F::Item) -> R
-where
-    F: Iterator<Item = R>,
-    // Both of the below bounds should be considered for `.into()`, and then be combined
-    // into a single `R: Into<?0>` bound which can be inferred to `?0 = R`.
-    F::Item: Into<K>,
-    R: Into<String>,
-{
-    q.into()
-}
-
-fn main() {}