linux-user/syscall_defs.h: Sync the latest si_code from Linux kernel They content several new macro members, also contents TARGET_N*. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Message-Id: <1443240605-2924-1-git-send-email-gang.chen.5i5j@gmail.com> Signed-off-by: Richard Henderson <rth@twiddle.net>