Harry Styles wasn’t just hitting his marks and showing off his dance moves in the music video for his newly released single “Aperture" ... he was taking hits too! A production source tells TMZ ... Harry personally handled the majority of the action stunts seen in the visually intense video -- including a gnarly staircase fall that took hours to nail ... roughly six hours and multiple takes to get right. We’re told the shoot went down over three days -- following a full week of rehearsals --