Addresses the post-commit review comments from the original PR (https://github.com/llvm/llvm-project/pull/217126#pullrequestreview-5162589053). - `SBFile::OpenFdFromHandle` is now visible on all platforms (just `#ifndef SWIG`) and returns -1 by default. - Removed non-stable `PyLong_Check` in favor of `PyErr_Occurred` and `PyErr_Clear`. (cherry picked from commit ba1687b72476eb368641b9a9f565a38cf41b7393)