TOKYO/SEOUL, March 31 (Reuters) - South Korea's Samsung Electronics Co Ltd (005930.KS) is considering setting up a chip test line in Japan, five people said, to bolster its advanced packaging business and forge closer ties with Japanese makers of semiconductor equipment and materials. It would be the first such test line for Samsung, the world's largest maker of memory chips, in Japan. It would also come as the United States increasingly urges allies to work together to counter China's rising might in chips and advanced technology. Japan on Friday said it will restrict exports of 23 types of chip-making tools,...