eval.c:2346
static VALUE
svalue_to_mrhs(v, lhs)
    VALUE v;
    NODE *lhs;
{
    VALUE tmp;

    if (v == Qundef) return rb_ary_new2(0);
    tmp = rb_check_array_type(v);
    if (NIL_P(tmp)) {
	return rb_ary_new3(1, v);
    }
    /* no lhs means splat lhs only */
    if (!lhs) {
	return rb_ary_new3(1, v);
    }
    return tmp;
}
