Auto merge of #129076 - matthiaskrgr:rollup-rg8mi2x, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #128410 (Migrate `remap-path-prefix-dwarf` `run-make` test to rmake)
 - #128759 (alloc: add ToString specialization for `&&str`)
 - #128873 (Add windows-targets crate to std's sysroot)
 - #129001 (chore(lib): Enhance documentation for core::fmt::Formatter's write_fm…)
 - #129061 (Use `is_lang_item` more)
 - #129062 (Remove a no-longer-true assert)

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

4 files changed, 26 insertions, 14 deletions

diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
index e77c738acce..05c79170902 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/note_and_explain.rs
@@ -4,6 +4,7 @@ use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
+use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams};
 use rustc_middle::ty::print::{FmtPrinter, Printer};
 use rustc_middle::ty::{self, suggest_constraining_type_param, Ty};
 use rustc_span::def_id::DefId;
@@ -313,11 +314,15 @@ impl<T> Trait<T> for X {
                     (ty::Dynamic(t, _, ty::DynKind::Dyn), _)
                         if let Some(def_id) = t.principal_def_id() =>
                     {
-                        let mut impl_def_ids = vec![];
+                        let mut has_matching_impl = false;
                         tcx.for_each_relevant_impl(def_id, values.found, |did| {
-                            impl_def_ids.push(did)
+                            if DeepRejectCtxt::new(tcx, TreatParams::ForLookup)
+                                .types_may_unify(values.found, tcx.type_of(did).skip_binder())
+                            {
+                                has_matching_impl = true;
+                            }
                         });
-                        if let [_] = &impl_def_ids[..] {
+                        if has_matching_impl {
                             let trait_name = tcx.item_name(def_id);
                             diag.help(format!(
                                 "`{}` implements `{trait_name}` so you could box the found value \
@@ -330,11 +335,15 @@ impl<T> Trait<T> for X {
                     (_, ty::Dynamic(t, _, ty::DynKind::Dyn))
                         if let Some(def_id) = t.principal_def_id() =>
                     {
-                        let mut impl_def_ids = vec![];
+                        let mut has_matching_impl = false;
                         tcx.for_each_relevant_impl(def_id, values.expected, |did| {
-                            impl_def_ids.push(did)
+                            if DeepRejectCtxt::new(tcx, TreatParams::ForLookup)
+                                .types_may_unify(values.expected, tcx.type_of(did).skip_binder())
+                            {
+                                has_matching_impl = true;
+                            }
                         });
-                        if let [_] = &impl_def_ids[..] {
+                        if has_matching_impl {
                             let trait_name = tcx.item_name(def_id);
                             diag.help(format!(
                                 "`{}` implements `{trait_name}` so you could change the expected \
@@ -346,11 +355,15 @@ impl<T> Trait<T> for X {
                     (ty::Dynamic(t, _, ty::DynKind::DynStar), _)
                         if let Some(def_id) = t.principal_def_id() =>
                     {
-                        let mut impl_def_ids = vec![];
+                        let mut has_matching_impl = false;
                         tcx.for_each_relevant_impl(def_id, values.found, |did| {
-                            impl_def_ids.push(did)
+                            if DeepRejectCtxt::new(tcx, TreatParams::ForLookup)
+                                .types_may_unify(values.found, tcx.type_of(did).skip_binder())
+                            {
+                                has_matching_impl = true;
+                            }
                         });
-                        if let [_] = &impl_def_ids[..] {
+                        if has_matching_impl {
                             let trait_name = tcx.item_name(def_id);
                             diag.help(format!(
                                 "`{}` implements `{trait_name}`, `#[feature(dyn_star)]` is likely \
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index 99ae342b54c..326a0e4e35c 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -230,8 +230,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                             post_message,
                         );
 
-                        let (err_msg, safe_transmute_explanation) = if Some(main_trait_ref.def_id())
-                            == self.tcx.lang_items().transmute_trait()
+                        let (err_msg, safe_transmute_explanation) = if self.tcx.is_lang_item(main_trait_ref.def_id(), LangItem::TransmuteTrait)
                         {
                             // Recompute the safe transmute reason and use that for the error reporting
                             match self.get_safe_transmute_error_and_reason(
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index 2c3adf73eee..d0f76f0d50e 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -2831,7 +2831,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                                     // Do not suggest relaxing if there is an explicit `Sized` obligation.
                                     && !bounds.iter()
                                         .filter_map(|bound| bound.trait_ref())
-                                        .any(|tr| tr.trait_def_id() == tcx.lang_items().sized_trait())
+                                        .any(|tr| tr.trait_def_id().is_some_and(|def_id| tcx.is_lang_item(def_id, LangItem::Sized)))
                                 {
                                     let (span, separator) = if let [.., last] = bounds {
                                         (last.span().shrink_to_hi(), " +")
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
index 294c6bfc124..d6687c762c3 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/prove_predicate.rs
@@ -1,3 +1,4 @@
+use rustc_hir::LangItem;
 use rustc_infer::traits::Obligation;
 pub use rustc_middle::traits::query::type_op::ProvePredicate;
 use rustc_middle::traits::query::NoSolution;
@@ -20,8 +21,7 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ProvePredicate<'tcx> {
         // such cases.
         if let ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_ref)) =
             key.value.predicate.kind().skip_binder()
-            && let Some(sized_def_id) = tcx.lang_items().sized_trait()
-            && trait_ref.def_id() == sized_def_id
+            && tcx.is_lang_item(trait_ref.def_id(), LangItem::Sized)
             && trait_ref.self_ty().is_trivially_sized(tcx)
         {
             return Some(());