Patrick Frater Asia Bureau ChiefThe shares of China’s largest entertainment and tech companies plunged for a second day on Tuesday as Russia’s war in Ukraine, regulatory warnings and China’s slowing economy all combined to signal tougher times ahead.Alibaba shares crashed 11.7% to reach an all-time low of HK$71.2 in Hong Kong, where they have a secondary listing. Tencent shares plunged by 10.2% to HK$298, their lowest in several years. Both companies have in the past held the title of China’s largest enterprise and are major components of the Hang Seng Index of leading equities.The Hang Seng Index fell by more than 1,000 points and by nearly 6% on Tuesday to close at 18,415.