Tag the current x86_64 branch as a current workable version of building x86_64 natively.
Preparing for some changes which should show the book as it might look supporting
both x86 and x86_64 in one.


git-svn-id: http://svn.linuxfromscratch.org/LFS/tags/x86_64-POC/BOOK@8277 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689