x86_64 port

by Alex Smith for Haiku

My proposal is an initial port of Haiku to the x86_64 architecture. While this is not a goal for R1, it is something that I think will benefit Haiku in the long term, as 64-bit CPUs are pretty much standard in PCs these days. It is unlikely that I will be able to complete a full port during the GSoC coding period, however it should be possible to complete at least a port of the boot loader, kernel and some modules/drivers, as well as possibly a small subset of userland.