bpo-46222: posixmodule sendfile FreeBSD's constants updates. (GH-30327)

* posixodule sendfile FreeBSD's constants updates.

* 📜🤖 Added by blurb_it.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>

Author: devnexen

Doc/library/os.rst

@@ -1429,6 +1429,15 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
 
    .. versionadded:: 3.3
 
+.. data:: SF_NOCACHE
+
+   Parameter to the :func:`sendfile` function, if the implementation supports
+   it. The data won't be cached in the virtual memory and will be freed afterwards.
+
+   .. availability:: Unix.
+
+   .. versionadded:: 3.11
+
 
 .. function:: splice(src, dst, count, offset_src=None, offset_dst=None)
 

Misc/NEWS.d/next/Library/2022-01-01-17-34-32.bpo-46222.s2fzZU.rst

@@ -0,0 +1 @@
+Adding ``SF_NOCACHE`` sendfile constant for FreeBSD for the posixmodule.

Modules/posixmodule.c

@@ -15170,12 +15170,16 @@ all_ins(PyObject *m)
 #ifdef SF_NODISKIO
     if (PyModule_AddIntMacro(m, SF_NODISKIO)) return -1;
 #endif
+    /* is obsolete since the 11.x release */
 #ifdef SF_MNOWAIT
     if (PyModule_AddIntMacro(m, SF_MNOWAIT)) return -1;
 #endif
 #ifdef SF_SYNC
     if (PyModule_AddIntMacro(m, SF_SYNC)) return -1;
 #endif
+#ifdef SF_NOCACHE
+    if (PyModule_AddIntMacro(m, SF_NOCACHE)) return -1;
+#endif
 
     /* constants for posix_fadvise */
 #ifdef POSIX_FADV_NORMAL