Christopher Vourlias Three mercenaries on the run with a plane full of gold and a dark secret in their past are the starting point for Jean Luc Herbulot’s Senegalese genre-bender “Saloum,” which has its world premiere in the Midnight Madness section of the Toronto Film Festival.The film centers on the Bangui Hyenas, a mythic trio of mercenaries whose plane is shot down as they’re fleeing a coup in Guinea-Bissau.