Update Fnctl with flags found in a modern fcntl.h file

[richardleach]

Module: Fcntl

Description
The Fnctl module is intended to be a translation of the C fcntl.h file, but it has clearly not kept up, since we recently merged 8acce4d and I've just raised #22071. It would be surprising if those are the only flags from a modern fcntl.h that we are missing.

Expected behavior
The Fnctl module contains all the flags you might find on a stable release of a mainstream Linux distro.

Perl configuration
Blead

[tonycoz]

Fixed by 22071