Joe Biden called out Donald Trump’s weight as he heckled his golf game during a particularly unhinged part of the first presidential debate, RadarOnline.com has learned. During one point in the debate, Biden, 81, and Trump, 78, were asked their thoughts on how age affected their ability to govern — and the ex-president pointed to his golf game as a measure of his fitness. Trump proudly exclaimed, “I just won two club championships, not even senior. Two regular club championships.” While pointing to his head, Trump added, “To do that, you have to be quite smart, and you have to be able to hit t…