Rollup merge of #111252 - matthewjasper:min-spec-improvements, r=compiler-errors

Min specialization improvements

- Don't allow specialization impls with no items, such implementations are probably not correct and only occur as mistakes in the compiler and standard library
- Fix a missing normalization call
- Adds spans for lifetime errors from overly general specializations

Closes #79457
Closes #109815

1 files changed, 3 insertions, 1 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs
index 402b09419c8..969e5fa64b0 100644
--- a/compiler/rustc_trait_selection/src/traits/coherence.rs
+++ b/compiler/rustc_trait_selection/src/traits/coherence.rs
@@ -322,7 +322,9 @@ fn negative_impl(tcx: TyCtxt<'_>, impl1_def_id: DefId, impl2_def_id: DefId) -> b
     let selcx = &mut SelectionContext::new(&infcx);
     let impl2_substs = infcx.fresh_substs_for_item(DUMMY_SP, impl2_def_id);
     let (subject2, obligations) =
-        impl_subject_and_oblig(selcx, impl_env, impl2_def_id, impl2_substs);
+        impl_subject_and_oblig(selcx, impl_env, impl2_def_id, impl2_substs, |_, _| {
+            ObligationCause::dummy()
+        });
 
     !equate(&infcx, impl_env, subject1, subject2, obligations, impl1_def_id)
 }