This replaces the old way of appending the memory bitmap to the end of the kernel, which started causing problems with expansion..
I hardcoded the value to 0x1440, which is the start of the first FREE block of memory given to SeaBIOS in QEMU. This should be changed in the future..
This was a doozy. I had to recompile gcc with a custom target to get it to output the CRT{BEGIN/END}.o files with proper 64 bit relocations.
The CMakeLists.txt file was also edited to allow these files to be linked (thereby actually adding the support) as well as to automatically create the boot image upon build.