[Projec64] Update code related to class friend

Source/Project64-core/N64System/N64Class.h

@@ -99,15 +99,15 @@ public:
     void   SyncSystemPC();
 private:
     //Make sure plugins can directly access this information
-    friend CGfxPlugin;
-    friend CAudioPlugin;
-    friend CRSP_Plugin;
-    friend CControl_Plugin;
+    friend class CGfxPlugin;
+    friend class CAudioPlugin;
+    friend class CRSP_Plugin;
+    friend class CControl_Plugin;
 
     //Recompiler has access to manipulate and call functions
-    friend CSystemTimer;
-    friend CRecompiler;
-    friend CMipsMemoryVM;
+    friend class CSystemTimer;
+    friend class CRecompiler;
+    friend class CMipsMemoryVM;
 
     //Used for loading and potentially executing the CPU in its own thread.
     static void StartEmulationThread(CThread * thread);

Source/Project64-core/Plugins/ControllerPlugin.h

@@ -80,7 +80,7 @@ public:
     inline uint32_t Buttons(void) const { return m_Buttons.Value; }
     inline PluginType Plugin(void) const { return static_cast<PluginType>(m_PlugType); }
 private:
-    friend CControl_Plugin; //controller plugin class has full access
+    friend class CControl_Plugin; //controller plugin class has full access
 
     int32_t & m_Present;
     int32_t & m_RawData;

Source/Project64/UserInterface/GuiClass.h

@@ -96,9 +96,9 @@ private:
     CMainGui(const CMainGui&);			// Disable copy constructor
     CMainGui& operator=(const CMainGui&);	// Disable assignment
 
-    friend CGfxPlugin;
-    friend CAudioPlugin;
-    friend CControl_Plugin;
+    friend class CGfxPlugin;
+    friend class CAudioPlugin;
+    friend class CControl_Plugin;
 
     bool RegisterWinClass(void);
     void ChangeWinSize(long width, long height);