refactor: Remove superfluous extern keyword from variable declarations

Core/GameEngine/Source/GameNetwork/GameSpy/PeerDefs.cpp

@@ -48,7 +48,7 @@
 
 
 GameSpyInfoInterface *TheGameSpyInfo = nullptr;
-extern GameSpyStagingRoom *TheGameSpyGame = nullptr;
+GameSpyStagingRoom *TheGameSpyGame = nullptr;
 void deleteNotificationBox();
 
 bool AsciiComparator::operator()(AsciiString s1, AsciiString s2) const

Generals/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DFileSystem.cpp

@@ -402,7 +402,7 @@ void GameFileClass::Close()
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 // W3DFileSystem Class ////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////////////////////////
-extern W3DFileSystem *TheW3DFileSystem = nullptr;
+W3DFileSystem *TheW3DFileSystem = nullptr;
 
 //-------------------------------------------------------------------------------------------------
 /** Constructor.  Creating an instance of this class overrides the default

Generals/Code/Tools/WorldBuilder/src/LayersList.cpp

@@ -870,4 +870,4 @@ END_MESSAGE_MAP()
 std::string LayersList::TheDefaultLayerName = "Default Layer";
 std::string LayersList::TheDefaultNewLayerName = "New Layer";
 const std::string LayersList::TheUnmutableDefaultLayerName = "Default Layer";
-extern LayersList *TheLayersList = nullptr;
+LayersList *TheLayersList = nullptr;

Generals/Code/Tools/WorldBuilder/src/RampOptions.cpp

@@ -79,7 +79,7 @@ void RampOptions::OnWidthChange()
 	m_rampWidth = atof(str.GetBuffer(0));
 }
 
-extern RampOptions* TheRampOptions = nullptr;
+RampOptions* TheRampOptions = nullptr;
 
 BEGIN_MESSAGE_MAP(RampOptions, COptionsPanel)
 	ON_BN_CLICKED(IDC_RO_APPLY, OnApply)

GeneralsMD/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DFileSystem.cpp

@@ -429,7 +429,7 @@ void GameFileClass::Close()
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 // W3DFileSystem Class ////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////////////////////////
-extern W3DFileSystem *TheW3DFileSystem = nullptr;
+W3DFileSystem *TheW3DFileSystem = nullptr;
 
 //-------------------------------------------------------------------------------------------------
 /** Constructor.  Creating an instance of this class overrides the default

GeneralsMD/Code/Tools/WorldBuilder/src/LayersList.cpp

@@ -1343,4 +1343,4 @@ std::string LayersList::TheDefaultNewLayerName = "New Layer";
 std::string LayersList::ThePolygonTriggerLayerName = "Default Trigger Layer";
 std::string LayersList::TheActiveLayerName;
 const std::string LayersList::TheUnmutableDefaultLayerName = "Default Object Layer";
-extern LayersList *TheLayersList = nullptr;
+LayersList *TheLayersList = nullptr;

GeneralsMD/Code/Tools/WorldBuilder/src/RampOptions.cpp

@@ -79,7 +79,7 @@ void RampOptions::OnWidthChange()
 	m_rampWidth = atof(str.GetBuffer(0));
 }
 
-extern RampOptions* TheRampOptions = nullptr;
+RampOptions* TheRampOptions = nullptr;
 
 BEGIN_MESSAGE_MAP(RampOptions, COptionsPanel)
 	ON_BN_CLICKED(IDC_RO_APPLY, OnApply)