Remove duplication of `BasicObject` constant; fix
MODIFY
src/class.c
src/class.c
@@ -2180,7 +2180,6 @@ mrb_init_class(mrb_state *mrb)
/* name basic classes */
mrb_define_const(mrb, bob, "BasicObject", mrb_obj_value(bob));
- mrb_define_const(mrb, obj, "BasicObject", mrb_obj_value(bob));
mrb_define_const(mrb, obj, "Object", mrb_obj_value(obj));
mrb_define_const(mrb, obj, "Module", mrb_obj_value(mod));
mrb_define_const(mrb, obj, "Class", mrb_obj_value(cls));

Remove duplication of `BasicObject` constant; fix #4698