Here are the remaining parts of the original 64bit XID patch set that I was able to apply manually, albeit with TBD's and FIXME's. I was unable to apply some small parts of the original patch set. What is contained here should 'git apply' cleanly today, but doesn't compile. It documents most of what was done with this approach in the hope that it will inform a future 64-bit table AM implementation about the many things that need to be considered.