One problem seems to be that the code added for this issue assumes that the documentation is correct in implying that the stat.FILE_ATTRIBUTE_* constants (like stat.FILE_ATTRIBUTE_REPARSE_POINT) are only present on Windows.  But besides being conditionally created in _stat.c, they are also undconditionally defined in stat.py on all platforms.  That makes some of the tests in shutil.py, like:
    if hasattr(stat, 'FILE_ATTRIBUTE_REPARSE_POINT'):
to determine which versions of _rmtree_islink and _rmtree_isdir to define problematic.