Islamist militants in the Philippines have freed a reporter with the Pan-Arabic Al-Arabiya news channel after holding him captive for 18 months, the Dubai-based broadcaster said.   Jordanian reporter Bakr Atyani, who was kidnapped in June 2012, is now free and receiving medical care in a hospital in the Philippines, said Mazen Hayek, spokesman for MBC, the parent group of Al-Arabiya.