5fe63ae9a3
This patch fixes a possible data race between main and event handler threads. Terminated event can be sent from `Disconnect` function or event handler. Consequently, there are some possible sequences of events. We must check events twice, because without getting an exited event, `exit_status` will be None. But, we don't know the order of events (for example, we can get terminated event before exited event), so we check events by filter. It is correct, because terminated event will be sent only once (guarded by `llvm::call_once`). This patch moved from [145010](https://github.com/llvm/llvm-project/pull/145010) and based on idea from this [comment](https://github.com/llvm/llvm-project/pull/145010#discussion_r2159637210).