Investigate recompiling libultra from ultralib

The n32 ABI is more efficient as it allows the use of 8 registers for passing arguments to functions instead of just 4. It also allows using the native 64 bit operations that the N64 supports. Compiling libultra under a modern compiler instead of a 25 year old one might also net some performance gain as well.

This task will be a very large undertaking and may not yield a large enough performance boost to warrant that amount of work, so it's not high priority.