Separate MxCore counter (#663)

LEGO1/omni/include/mxcore.h

@@ -38,6 +38,7 @@ public:
 	// MxCore::`scalar deleting destructor'
 
 private:
+	static MxU32 g_nextCoreId;
 	MxU32 m_id; // 0x04
 };
 

LEGO1/omni/include/mxsoundmanager.h

@@ -22,7 +22,7 @@ public:
 
 	inline LPDIRECTSOUND GetDirectSound() { return m_directSound; }
 
-	MxS32 FUN_100aecf0(MxU32 p_undefined);
+	MxS32 GetAttenuation(MxU32 p_volume);
 
 protected:
 	void Init();