When pytest was run on a directory containing a recursive symlink it failed
with ELOOP as the library was not able to determine the type of the
direntry:
src/_pytest/main.py:685: in collect
if not direntry.is_file():
E OSError: [Errno 40] Too many levels of symbolic links: '/home/florian/proj/pytest/tests/recursive'
This is fixed by handling ELOOP and other errors in the visit function in
pathlib.py, so the entries whose is_file() call raises an OSError with the
pre-defined list of error numbers will be exluded from the result.
The _ignore_errors function was copied from Lib/pathlib.py of cpython 3.9.
Fixes#7951
8a38e7a6e8