[IR] Implement shmem header

include/services/ir_user.hpp

@@ -24,6 +24,25 @@ class IRUserService {
 	void requireConnection(u32 messagePointer);
 
 	std::optional<Handle> connectionStatusEvent = std::nullopt;
+	std::optional<MemoryBlock> sharedMemory = std::nullopt;
+	bool connectedDevice = false;
+
+	// Header of the IR shared memory containing various bits of info
+	// https://www.3dbrew.org/wiki/IRUSER_Shared_Memory
+	struct SharedMemoryStatus {
+		u32 latestReceiveError;
+		u32 latestSharedError;
+
+		u8 connectionStatus;
+		u8 connectionAttemptStatus;
+		u8 connectionRole;
+		u8 machineID;
+		u8 isConnected;
+		u8 networkID;
+		u8 isInitialized;  // https://github.com/citra-emu/citra/blob/c10ffda91feb3476a861c47fb38641c1007b9d33/src/core/hle/service/ir/ir_user.cpp#L41
+		u8 unk1;
+	};
+	static_assert(sizeof(SharedMemoryStatus) == 16);
 
   public:
 	IRUserService(Memory& mem, Kernel& kernel) : mem(mem), kernel(kernel) {}