Chinese President Xi Jinping is expected to visit Saudi Arabia by the end of this year as the world’s top oil importer and the top oil exporter strengthen energy and strategic ties while U.S.-Saudi relations are at a historically low level. China’s Xi is set to meet with Saudi Arabia’s Crown Prince Mohammed bin Salman during a visit to the Kingdom expected to take place this month or next, sources with knowledge of the preparations for the official visit told The Wall Street Journal on Monday. China – the world’s…