[llvm] [lit] Echo full RUN lines in case of external shells (PR #65267)

[Joel E. Denny via llvm-commits]

jdenny-ornl wrote:

@jsji Thanks for alerting me to the bot fails.  The revert seems to have fixed at list one bot.  Did you see any additional clue in the logs about what happened?  All I see is:

```
remoteFailed: [Failure instance: Traceback (failure with no frames): <class 'twisted.internet.error.ConnectionLost'>: Connection to the other side was lost in a non-clean fashion.
]
```

 I don't know how to debug that.

https://github.com/llvm/llvm-project/pull/65267