[llvm] [z/OS] Modify regex in error message to match on z/OS. (PR #194020)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

You would need to import the LLVM config:
```python
from lit.llvm import llvm_config
```

And then call this function:

https://github.com/llvm/llvm-project/blob/0e6d57648584c3895abd3021fb8fa2a767146d5a/llvm/utils/lit/lit/llvm/config.py#L470

None of the other lit tests do that currently, but I don't think there should be any major issues with doing so.

https://github.com/llvm/llvm-project/pull/194020