From: "Randy.Dunlap" <rddunlap@osdl.org>

kexec is a fairly major and popular feature.  People are shipping it in
products, although it is not known if Linux distributors plan to ship it.

The patch reserves the kexec syscall slots to pin the ABI down for
everyone.


- add kexec_load prototype to syscalls.h

- add LINUX_REBOOT_CMD_KEXEC to reboot.h

- add kexec_load syscall for ia32, ia64, x86_64, ppc32, ppc64