class.c: no need to create aliases if both symbols are same.
@@ -2197,6 +2197,7 @@ mrb_obj_class(mrb_state *mrb, mrb_value obj)
MRB_API void
mrb_alias_method(mrb_state *mrb, struct RClass *c, mrb_sym a, mrb_sym b)
{
+ if (a == b) return;
mrb_method_t m = mrb_method_search(mrb, c, b);
if (!MRB_METHOD_CFUNC_P(m)) {
