Refactor NDS and DSi to be objects (#1893)

* 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`

src/frontend/qt_sdl/ROMManager.h

@@ -24,10 +24,19 @@
 #include "AREngine.h"
 #include "DSi_NAND.h"
 
+#include "MemConstants.h"
+#include <optional>
 #include <string>
 #include <memory>
 #include <vector>
 
+namespace melonDS
+{
+class NDS;
+class DSi;
+class FATStorage;
+}
+class EmuThread;
 namespace ROMManager
 {
 
@@ -37,30 +46,41 @@ extern SaveManager* GBASave;
 extern std::unique_ptr<SaveManager> FirmwareSave;
 
 QString VerifySetup();
-void Reset();
-bool LoadBIOS();
+void Reset(EmuThread* thread);
+bool LoadBIOS(EmuThread* thread);
 void ClearBackupState();
 
-bool InstallFirmware();
-bool InstallNAND(const u8* es_keyY);
-bool LoadROM(QStringList filepath, bool reset);
-void EjectCart();
+std::optional<std::array<u8, ARM9BIOSSize>> LoadARM9BIOS() noexcept;
+std::optional<std::array<u8, ARM7BIOSSize>> LoadARM7BIOS() noexcept;
+std::optional<std::array<u8, DSiBIOSSize>> LoadDSiARM9BIOS() noexcept;
+std::optional<std::array<u8, DSiBIOSSize>> LoadDSiARM7BIOS() noexcept;
+std::optional<FATStorage> LoadDSiSDCard() noexcept;
+void CustomizeFirmware(Firmware& firmware) noexcept;
+Firmware GenerateFirmware(int type) noexcept;
+/// Loads and customizes a firmware image based on the values in Config
+std::optional<Firmware> LoadFirmware(int type) noexcept;
+/// Loads and customizes a NAND image based on the values in Config
+std::optional<DSi_NAND::NANDImage> LoadNAND(const std::array<u8, DSiBIOSSize>& arm7ibios) noexcept;
+bool InstallFirmware(NDS& nds);
+bool InstallNAND(DSi& dsi);
+bool LoadROM(EmuThread*, QStringList filepath, bool reset);
+void EjectCart(NDS& nds);
 bool CartInserted();
 QString CartLabel();
 
-bool LoadGBAROM(QStringList filepath);
-void LoadGBAAddon(int type);
-void EjectGBACart();
+bool LoadGBAROM(NDS& nds, QStringList filepath);
+void LoadGBAAddon(NDS& nds, int type);
+void EjectGBACart(NDS& nds);
 bool GBACartInserted();
 QString GBACartLabel();
 
 std::string GetSavestateName(int slot);
 bool SavestateExists(int slot);
-bool LoadState(const std::string& filename);
-bool SaveState(const std::string& filename);
-void UndoStateLoad();
+bool LoadState(NDS& nds, const std::string& filename);
+bool SaveState(NDS& nds, const std::string& filename);
+void UndoStateLoad(NDS& nds);
 
-void EnableCheats(bool enable);
+void EnableCheats(NDS& nds, bool enable);
 ARCodeFile* GetCheatFile();
 
 void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32 (&iconRef)[32*32]);