Rollup merge of #145095 - tiif:unstable_const_param, r=BoxyUwU

Migrate `UnsizedConstParamTy`  to unstable impl of `ConstParamTy_`

Now that we have ``#[unstable_feature_bound]``, we can remove ``UnsizedConstParamTy`` that was meant to be an unstable impl of stable type and ``ConstParamTy_`` trait.

r? `@BoxyUwU`

1 files changed, 3 insertions, 12 deletions

diff --git a/compiler/rustc_hir_analysis/src/coherence/builtin.rs b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
index 32b175611ce..0b9a01d6042 100644
--- a/compiler/rustc_hir_analysis/src/coherence/builtin.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/builtin.rs
@@ -1,7 +1,6 @@
 //! Check properties that are required by built-in traits and set
 //! up data structures required by type-checking/codegen.
 
-use std::assert_matches::assert_matches;
 use std::collections::BTreeMap;
 
 use rustc_data_structures::fx::FxHashSet;
@@ -40,10 +39,7 @@ pub(super) fn check_trait<'tcx>(
     checker.check(lang_items.async_drop_trait(), visit_implementation_of_drop)?;
     checker.check(lang_items.copy_trait(), visit_implementation_of_copy)?;
     checker.check(lang_items.const_param_ty_trait(), |checker| {
-        visit_implementation_of_const_param_ty(checker, LangItem::ConstParamTy)
-    })?;
-    checker.check(lang_items.unsized_const_param_ty_trait(), |checker| {
-        visit_implementation_of_const_param_ty(checker, LangItem::UnsizedConstParamTy)
+        visit_implementation_of_const_param_ty(checker)
     })?;
     checker.check(lang_items.coerce_unsized_trait(), visit_implementation_of_coerce_unsized)?;
     checker
@@ -138,12 +134,7 @@ fn visit_implementation_of_copy(checker: &Checker<'_>) -> Result<(), ErrorGuaran
     }
 }
 
-fn visit_implementation_of_const_param_ty(
-    checker: &Checker<'_>,
-    kind: LangItem,
-) -> Result<(), ErrorGuaranteed> {
-    assert_matches!(kind, LangItem::ConstParamTy | LangItem::UnsizedConstParamTy);
-
+fn visit_implementation_of_const_param_ty(checker: &Checker<'_>) -> Result<(), ErrorGuaranteed> {
     let tcx = checker.tcx;
     let header = checker.impl_header;
     let impl_did = checker.impl_def_id;
@@ -157,7 +148,7 @@ fn visit_implementation_of_const_param_ty(
     }
 
     let cause = traits::ObligationCause::misc(DUMMY_SP, impl_did);
-    match type_allowed_to_implement_const_param_ty(tcx, param_env, self_type, kind, cause) {
+    match type_allowed_to_implement_const_param_ty(tcx, param_env, self_type, cause) {
         Ok(()) => Ok(()),
         Err(ConstParamTyImplementationError::InfrigingFields(fields)) => {
             let span = tcx.hir_expect_item(impl_did).expect_impl().self_ty.span;