When calculating the size of the undisplayed margin in the case where
fbWidth != fbStride for RealXFB for displaying in the output window,
we do not scale by IR - RealXFB is implicitly 1x.
These were only compiled in on Windows and x86_32.
They provided "optimized" copies and compares based on blocksizes for the AMD Athlon and Duron CPU families.
The code was taken from something that AMD provides with a as-is license.
Just get rid of this crap.
Our defines were never clear between what meant 64bit or x86_64
This makes a clear cut between bitness and architecture.
This commit also has the side effect of bringing up aarch64 compiling support.
