Make x86-64 boot again after the INITIAL_JIFFIES changes
and some bug fixes. Also some work for NPTL.

 - Merge with i386/2.5.64-bk3
 - Fix memory leak in copy_thread
 - arch_prctl uses GDT for base if possible. Cleanup.
 - clone supports bases >32bit for SETTLS etc. %fs hardcoded now.
 - new ptrace support for 64bit TLS
 - Disable (set|get)_thread_* for 64bit processes.
 - Audit arch/x86_64 for jiffies wrap issues.
 - Fix initial jiffies problem (that caused hanging kernels)
 - FIx a few 32bit emulation bugs (sigaltstack, sigqueue)
 - Some cleanup from Pavel
 - Should compile again as UP
 - Shrink size a bit by not putting exception tables into object files.
 - Fix compilation with gcc 3.3 :- force inlining when needed
 - Work around 2.5.64-bk3 console init bug.
 - Fix some alignments in assembly code