Avoid array copying in `mrb_instance_new`.
MODIFY
src/class.c
src/class.c
@@ -1487,7 +1487,7 @@ mrb_instance_new(mrb_state *mrb, mrb_value cv)
mrb_int argc;
mrb_sym init;
- mrb_get_args(mrb, "*&", &argv, &argc, &blk);
+ mrb_get_args(mrb, "*!&", &argv, &argc, &blk);
obj = mrb_instance_alloc(mrb, cv);
init = mrb_intern_lit(mrb, "initialize");
if (!mrb_func_basic_p(mrb, obj, init, mrb_bob_init)) {

Avoid array copying in `mrb_instance_new`.