llvm-project

61564476 - lit: Handle permission errors in runCommandCached (#208508)

lit: Handle permission errors in runCommandCached (#208508) The downstream swift CI is getting PermissionError instead of FileNotFoundError for a [couple of tests](https://ci.swift.org/job/pr-apple-llvm-project-llvm-linux/1819/consoleFull#-556494529d6fdb6cb-f376-4f2e-8bce-d31c7304698b). I have no idea what is wrong with our CI, but we should be handling those errors the same way anyway. Also fix documentation typo.