* First crack at refactoring NDS and DSi into objects
- Remove all global/`static` variables in `NDS` and related classes
- Rely more on virtual dispatch when we need to pick methods at runtime
- Pass `NDS&` or `DSi&` to its constituent components where necessary
- Introduce some headers or move some definitions to break `#include` cycles
* Refactor the frontend to accommodate the core's changes
* Move up `SchedList`'s declaration
- Move it to before the components are initialized so the `map`s inside are initialized
- Fields in C++ are initialized in the order they're declared
* Fix a crash when allocating memory
* Fix JIT-free builds
* Fix GDB-free builds
* Fix Linux builds
- Explicitly qualify some member types in NDS, since they share the same name as their classes
* Remove an unnecessary template argument
- This was causing the build to fail on macOS
* Fix ARM and Android builds
* Rename `Constants.h` to `MemConstants.h`
* Add `NDS::IsRunning()`
* Use an `#include` guard instead of `#pragma once`
Arisotura