By Gregor Stuart Hunter SINGAPORE (Reuters) -Asian stocks fell for a second day on Thursday as lacklustre earnings from tech megacaps deepened a selloff on Wall Street, while U.S. sanctions against Russia and possible new export controls on China revived geopolitical worries. Oil prices surged 3% after the U.S. imposed sanctions on major Russian companies Rosneft and Lukoil over the Ukraine war. MSCI's broadest index of Asia-Pacific shares outside Japan was last off 0.4%, while Japan's Nikkei 225 sank 1 ...