This is necessary for ZFS systems, which don't support UF_IMMUTABLE.

(Note: this commit is a manual merge of 78699:019a2390b014 as both
_test_chflags_regular_file and test_lchflags_symlink differ between
3.2 and default.)

This is necessary for ZFS systems, which don't support UF_IMMUTABLE.

os.sched_setaffinity now use regular sets of integers to represent the
CPUs a process is restricted to.

Skip test in freebsd entirely - Kernel bug in freebsd7/8/9 - #10142: Support for SEEK_HOLE/SEEK_DATA

of os.listdir().

Many functions now support "dir_fd" and "follow_symlinks" parameters;
some also support accepting an open file descriptor in place of of a path
string.  Added os.support_* collections as LBYL helpers.  Removed many
functions only previously seen in 3.3 alpha releases (often starting with
"f" or "l", or ending with "at").  Originally suggested by Serhiy Storchaka;
implemented by Larry Hastings.

associated pwd entry.

chown() to root under certain circumstances.

be consistent with other functions accepting file descriptors (fdlistdir() was
added in 3.3, so hasn't been released yet).

descriptor (instead of closing it).

can be called again on the same open file).

defaulting to None like the other utimes family members. It now accepts
keyword arguments because, unlike other other functions in the family,
it has a `flags` value at the end of the argument list (which
retains its 0 default).

and lutimes.

used with sys.setdlopenflags().

<sched.h> is available (most notably on OpenBSD when built without pthread):
add an explicit configure check.

sched_setparam() returning EINVAL for processes with SCHED_OTHER scheduling
policy.

link file name.

We don't need to create a temporary buffered binary or text file object just to
create an empty file.

Replace also os.fdopen(handle).close() by os.close(handle).

os.lchflags() are once again built on systems that support these
functions (*BSD and OS X).  Also add new stat file flags for OS X
(UF_HIDDEN and UF_COMPRESSED).  Also add additional tests for
os.chflags() and os.lchflags(). (Tests by Garrett Cooper)