Eliminate boilerplate of having each test manually assign to `mydir` by calling `compute_mydir` in lldbtest.py. Differential Revision: https://reviews.llvm.org/D128077
`SBError::SetErrorToGenericError` should call `Status::SetErrorToGenericError`, not `Status::SetErrorToErrno`. Reviewed By: teemperor Differential Revision: https://reviews.llvm.org/D90151