Inconsistent handling of `directory_options::skip_permission_denied`

[gulrak]

Describe the bug
While testing the POSIX implementation of the recursive_directory_iterator on macOS, I found the skip_permission_deniedoption to not work when iterating over my complete home directory hitting the ~/Library/Application Support/MobileSync folder. The increment still threw a filesystem_error. The reason is not wrong permissions, but "System Integrety Protection". The opendir results in an EPERM and not EACESS, and while EPERM was added to the increment handling of directory_iterator it is missing from the opendir error handling.

To Reproduce
Just try to iterate over a macOS SIP protected folder.

Expected behavior
The iterator should not enter the protected folder but continue to scan next to it.

[gulrak]

Released with v1.3.8