Replace x86-64 paccept with accept4

This patch changes the paccept syscall to accept4 for x86-64, since
the former was dropped in Linux kernel commit v2.6.27-rc7-14-g2d4c826.
At the same time, it adds support for pretty printing its arguments.

* linux/x86_64/syscallent.h: Replace paccept with accept4,
hook in sys_accept4.
* net.c (sys_accept): Leave a small stub calling the new...
(do_accept): ... function, which also adds a flags_arg argument.
(sys_accept4): New.
3 files changed