https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86943
--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> --- pt.c calls here: ret = (build_new_method_call (instance, fn, &call_args, NULL_TREE, qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL, /*fn_p=*/NULL, complain)); and doesn't in any way tell it that CALL_FROM_THUNK_P (t) is true and that it should avoid some or all? argument conversions. Or shall it call a different function in that case instead? In any case, not working on this PR anymore.