Fix handling recursive symlinks

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

1 files changed, 1 insertions, 0 deletions

diff --git a/AUTHORS b/AUTHORS
index 35d220e00..f8d3d421c 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -314,3 +314,4 @@ Xuecong Liao
 Yoav Caspi
 Zac Hatfield-Dodds
 Zoltán Máté
+Zsolt Cserna