PHOENIX — Some Jewish residents are trying to legally block use of the gas chamber for future executions, calling it barbaric, cruel and unusual — and a painful reminder of the Holocaust for survivors who live here. A lawsuit filed by the Jewish Community Relations Council of Greater Phoenix and two of its members acknowledges that Arizona voters in 1992 eliminated the use of lethal gas, replacing it with lethal injections. That followed gruesome reports of the execution of Don Harding, who took 11 minutes to die. But that 1992 constitutional amendment, approved by a margin of more than 3-1,...