[llvm] [symbolizer] Empty string is not an error (PR #92660)

[via llvm-commits]

pcc wrote:

I answered it earlier:

> A good response means that the client program found the llvm-symbolizer executable and it reached its main loop, which is a useful thing to know on its own regardless of whether later requests fail. A bad response is a strong signal (not a guarantee) that there was a user error and the client program should tell the user to e.g. check their $PATH. A good response rules out this type of user error and means that if we see a crash later it means that there is a bug (either in the client program or llvm-symbolizer) and the client program can respond by telling the user to file a bug report.

Maybe the client program should always tell the user to check their $PATH if the read fails? But it seems like that could be confusing for users if there is an actual bug.

https://github.com/llvm/llvm-project/pull/92660