ISLAMABAD — Mohammad Ashfaq, a villager in Pakistan’s Punjab province, came to the village council with a harrowing complaint: His 12-year-old sister had been raped by a 15-year-old boy, a distant cousin. The council, or jirga, prescribed an equally harrowing punishment: Ashfaq, 20, should publicly rape the boy’s sister, who is 16. Ashfaq carried out the…