Auto merge of #115817 - fee1-dead-contrib:fix-codegen, r=oli-obk

treat host effect params as erased in codegen

This fixes the changes brought to codegen tests when effect params are added to libcore, by not attempting to monomorphize functions that get the host param by being `const fn`.

r? `@oli-obk`

compiler/rustc_ty_utils/src/instance.rs

@@ -55,6 +55,7 @@ fn resolve_instance<'tcx>(
             }
         } else {
             debug!(" => free item");
+            // FIXME(effects): we may want to erase the effect param if that is present on this item.
             ty::InstanceDef::Item(def_id)
         };