* cannon: 64-bit Refactor

Refactor Cannon codebase to support both 32-bit and 64-bit MIPS emulation
while reusing code as much as possible.

* fix 64-bit test compilation errors

* review comments

* more review comments

* fcntl syscall err for 64-bit

* simplify pad check

* cannon: sc must store lsb 32 on 64-bits

* lint

* fix sc 64-bit logic

* add TODO state test