Make our architecture defines less stupid.
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.
Merge pull request #120 from Sonicadvance1/Arch-clean

Make our architecture defines less stupid.
OS X likes to be different. It reports the host processor type as i386 instead of x86 or x86_64 like a typical sane system.
Merge pull request #132 from Sonicadvance1/Arch-clean

OS X likes to be different. It reports the host processor type as i386 i...