Some big refactors:
* improve scheduler performance by using a BinaryHeap
* refactor the scheduler API
* arm7tdmi
* Change struct arm7tdmi::Core struct layout so frequently accesses fields would benefit from CPU cache
* Simplify and cleanup cycle counting by implementing a MemoryInterface trait
* Still not passing many cycle accuracy tests, but I believe it's because I don't have the prefetch buffer yet.
* Timer overflows are now scheduled
* This fixes#111 and fixes#112
*
Former-commit-id: 17989e841a1ea88c2a7e14f4c99b31790a43c023
Former-commit-id: 109d98d824a464de347f6590a6ffe9af86b4b4ea
Avoid passing ArmInstruction struct to handlers, as accesses to its fields can result in memory operations.
Former-commit-id: 6ea1719e36a0fefa1b30bdae4d6e8ab4dbf3af1a
Former-commit-id: e5855b8258f98d3f4c0819f3aec2fd0f47fef545
