- Stop using inheritance for CPU, instead use composition.

- Introduce KAIZEN_JIT_ENABLED optional define instead of relying on __aarch64__ and the like.
- More cache work

src/backend/core/Cache.hpp

@@ -0,0 +1,27 @@
+#pragma once
+#include <common.hpp>
+
+namespace n64 {
+struct alignas(32) InstructionCache {
+    bool valid;
+    u32 data[8];
+    u32 ptag;
+
+  private:
+    friend struct Interpreter;
+    int GetLineIndex(u64 vaddr) { return (vaddr >> 5) & 0x1FF; }
+    u32 GetLineStart(u64 paddr) { return paddr & ~0x1F; }
+};
+
+struct alignas(32) DataCache {
+    bool valid, dirty;
+    u8 data[16];
+    u32 ptag;
+    int index;
+
+  private:
+    friend struct Interpreter;
+    int GetLineIndex(u64 vaddr) { return (vaddr >> 4) & 0x1FF; }
+    u32 GetLineStart(u64 paddr) { return paddr & ~0xF; }
+};
+} // namespace n64