Arthur Fils and Ugo Humbert ground out hard-fought semifinal wins at the Japan Open tennis tournament on Monday, setting up an all-French final between the Paris Olympics men’s doubles partners. World No. 24 Fils prevailed in a 2-hour, 23-minute marathon match against Holger Rune 7-6(8), 7-6(10). The 14th-ranked Dane had beaten his fellow former world No. 4 and Japan’s home favorite Kei Nishikori 3-6, 6-2, 7-5 in the last eight on Sunday. Also at Tokyo’s Ariake Colosseum, 19th-ranked Humbert downed 34th-ranked Tomas Machac of the Czech Republic 6-3, 3-6, 6-2. Fils and Humbert went out in the m…