As the trading week winds down on Friday and heads into the holidays, there's big trouble brewing in China's big tech sector. Shares of online gaming company NetEase (NTES -15.18%) crashed 15% through noon today, while Huya (HUYA -10.19%), a specialist in livestreaming of online games, fell 10.7% in response to rumored regulations coming down from the Chinese government.Gaotu Techedu (GOTU -8.33%), which isn't a gaming company at all but rather a for-profit educator, seemed to fall in sympathy with its gami ...