MADRID — One of the grand old men of Spanish cinema, Francisco Rabal, died Wednesday afternoon while returning from a tribute to him at the Montreal Film Festival.The 75-year-old was taken ill with pulmonary complications on the flight from London to Madrid and died as the plane was making an emergency stop in Bordeaux. A leading man in 1950s Spanish films, Rabal starred in some of Luis Bunuel’s greatest films, including “Nazarin” (1958), “Viridiana” (1961) and “Belle de Jour” (1966). He shared the best actor trophy at the 1984 Cannes Intl. Film Festival for his perf as the idiot savant in Mario Camus’ “The Holy Innocents.” Rabal was to have received a Donostia lifetime achievement award at the San Sebastian Film Festival. The fest will dedicate a tribute to him.