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`

1 files changed, 35 insertions, 0 deletions

diff --git a/src/MemConstants.h b/src/MemConstants.h
new file mode 100644
index 0000000..ab80fab
--- /dev/null
+++ b/src/MemConstants.h
@@ -0,0 +1,35 @@
+/*
+    Copyright 2016-2023 melonDS team
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef MELONDS_MEMCONSTANTS_H
+#define MELONDS_MEMCONSTANTS_H
+
+#include "types.h"
+
+namespace melonDS
+{
+constexpr u32 MainRAMMaxSize = 0x1000000;
+constexpr u32 SharedWRAMSize = 0x8000;
+constexpr u32 ARM7WRAMSize = 0x10000;
+constexpr u32 NWRAMSize = 0x40000;
+constexpr u32 ARM9BIOSSize = 0x1000;
+constexpr u32 ARM7BIOSSize = 0x4000;
+constexpr u32 DSiBIOSSize = 0x10000;
+}
+
+#endif // MELONDS_MEMCONSTANTS_H
\ No newline at end of file