CDROM: Implement get version and getstat commands

src/common/bitfield.h

@@ -88,7 +88,7 @@ struct BitField
 
   BitField& operator|=(DataType rhs)
   {
-    SetValue(GetValue() & rhs);
+    SetValue(GetValue() | rhs);
     return *this;
   }
 

src/common/fifo_queue.h

@@ -20,7 +20,7 @@ public:
   T* GetFrontPointer() { return m_ptr[m_head]; }
   constexpr u32 GetCapacity() const { return CAPACITY; }
   u32 GetSize() const { return m_size; }
-  bool IsEmpty() const { return m_size > 0; }
+  bool IsEmpty() const { return m_size == 0; }
   bool IsFull() const { return m_size == CAPACITY; }
 
   void Clear()