Halle Berry just showed up her "Kingsman: The Golden Circle" co-stars ... by taking their shots of whiskey and raising them a whole damn glass.

Halle and the cast were on a panel at San Diego's Comic-Con Thursday when they started passing around shots. Channing Tatum poured her about 5 shots worth into a pint and, after intense peer pressure from the crowd ... she slammed it!

More proof she's definitely not pregnant ... if ya needed that.

Someone's going to bed early tonight.