Duplicate ~const bounds with a non-const one in effects desugaring

compiler/rustc_middle/src/ty/generics.rs

@@ -79,6 +79,10 @@ impl GenericParamDef {
         }
     }
 
+    pub fn is_host_effect(&self) -> bool {
+        matches!(self.kind, GenericParamDefKind::Const { is_host_effect: true, .. })
+    }
+
     pub fn default_value<'tcx>(
         &self,
         tcx: TyCtxt<'tcx>,