BEIJING (Reuters) -Japan's Toyota Motor will pair up with China's Tencent while Nissan will team up with Baidu, the companies said on Thursday, cross-border partnerships that highlight the importance of artificial intelligence for carmakers. The separate announcements from two of Japan's biggest automakers at the Beijing auto show also underscored the attempt by Japanese manufacturers to come to grips with the massive technological shifts that have disrupted their once enviable positions in the Chinese market.