PMM Buddy Allocator done!

The PMM now uses a buddy allocator which gives us many advantages, including:

• Tracking overhead doesn’t grow with RAM size
• Faster (bitmap is always O(n), buddy allocator is O(1) most times, worst case O(log n))
• Order-based allocation (group a lot of free space together into one 4 MiB region for order 10 or 16 KiB for order 2 for example)

Next is adding a few methods to the VMM, and then I’ll work on the heap allocator to finally be able to work on the kstate struct :)