Notwithstanding any other provision of law, the governing body of any county or city, in its discretion, may supplement the compensation of the sheriff, treasurer, commissioner of the revenue, director of finance, clerk of the circuit court, or attorney for the Commonwealth, or any of their deputies or employees, above the salary of any such officer, deputy or employee, in such amounts as it may deem expedient. Such additional compensation shall be wholly payable from the funds of any such county or city.