[libcxx-commits] [libcxx] [lit] Clean up internal shell parse errors with ScriptFatal (PR #68496)

[Alexander Richardson via libcxx-commits]

https://github.com/arichardson approved this pull request.

LGTM (especially with the `from typing import Optional, Tuple` suggestion applied).

https://github.com/llvm/llvm-project/pull/68496