[lit] Fix lit hang on pool join when exception is thrown (#131881)

Fixes #133914

When using the internal shell with a timeout set lit will hang on the
following call if an exception is thrown and not immediately caught
https://github.com/llvm/llvm-project/blob/19970535f92c0f2dcda01b7fc60f95945166e424/llvm/utils/lit/lit/run.py#L93

This can occur when using the internal lit shell and trying to run a
program that does not exist. In this case `_executeShCmd` will throw an
internal shell error, which will not be caught by the function directly
calling it, `executeShCmd`, rather it is caught one function higher in
the call stack in `executeScriptInternal`. Because that exception is
percolated up the call stack instead of being immediately caught lit
will hang until the test timeout expires. This patch changes the
location where we catch this exception to `executeShCmd` instead to
avoid this.

For more background on what causes this hang see:

https://stackoverflow.com/questions/15314189/python-multiprocessing-pool-hangs-at-join
4 files changed
tree: bcb28aaabebee049304bddfcb02edac6a3b59cb4
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-format-ignore
  30. .clang-tidy
  31. .git-blame-ignore-revs
  32. .gitattributes
  33. .gitignore
  34. .mailmap
  35. CODE_OF_CONDUCT.md
  36. CONTRIBUTING.md
  37. LICENSE.TXT
  38. pyproject.toml
  39. README.md
  40. SECURITY.md
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