This brings the x86-64 port uptodate in 2.5.60. Unfortunately I cannot
test too much because i constantly get deadlocks in exit/wait in initscripts
on SMP bootup. The kernel seems to still lose a lot of SIGCHLD. 2.5.59/SMP
had the same problem. Uniprocessor and SMP kernel on UP seems to work.

This patch only touches x86-64 specific files. It requires a few simple
changes to arch independent files that I will send separately.

 - Fixed a lot of obsolete/misleading configure help texts.
 - Remove old bootblock disk loader and support fdimage target for syslinux
   instead (H. Peter Anvin)
 - Fix potential fpu signal restore problem on 32bit emulation.
 - Merge with 2.5.60 i386 (hugetlbfs, acpi etc.)
 - Some fixes for local apic disabled modus.
 - Beginngs of S3 ACPI wakeup from real-mode (not working yet, don't use)
 - Beginnings of NUMA/CONFIG_DISCONTIGMEM support for AMD K8 (work in progress,
   port from 2.4): clean up memory mapping at bootup, generalize bootmem etc.
 - Fix 64bit GS base reload problem and reenable (Karsten Keil)
 - Fix race with vmalloc accesses from interrupt handlers disturbing page fault/
   similar race for the debug handler (thanks to Andrew Morton)
 - Merge cpu access primitives with i386
 - Revert to private module list for now because putting modules
   nto vmlist triggered too many problems.
 - Some cleanups, removal of unneeded code.
 - Let early __get_free_pages see consistent pda
 - Preempt disabled for now because it is too broken right now
 - Signal handler fixes
 - Fix do_gettimeofday to be completely lockless and reenable vsyscalls
 - Optimize context switch path a bit (should be ported to i386)
 - Get thread_info via stack for better code
 - Don't leak pmd pages
 - Clean up hardcoded task stack sizes.