[llvm] [Coroutines] Always set the calling convention of generated resuming call from 'llvm.coro.await.suspend.handle' as fast (PR #93167)

[Chuanqi Xu via llvm-commits]

ChuanqiXu9 wrote:

I'll land this to give it a try. Feel free to revert it if the bots alert again and I don't respond in time.

https://github.com/llvm/llvm-project/pull/93167