Do export wxMSWOwnerDrawnButton from DLL in wxMSW.

This class shouldn't need to be exported but not doing it breaks builds using
LTCG with Intel compiler, so do export it to avoid this problem.

Closes #16237.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76485 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/checkbox.h

@@ -13,13 +13,6 @@
 
 #include "wx/msw/ownerdrawnbutton.h"
 
-#ifdef __VISUALC__
-    // Disable the warning about non DLL-exported wxMSWOwnerDrawnButton class
-    // used as base for DLL-exported class: it's harmless in this case.
-    #pragma warning(push)
-    #pragma warning(disable:4275)
-#endif
-
 // Checkbox item (single checkbox)
 class WXDLLIMPEXP_CORE wxCheckBox : public wxMSWOwnerDrawnButton<wxCheckBoxBase>
 {
@@ -84,8 +77,4 @@ private:
     DECLARE_DYNAMIC_CLASS_NO_COPY(wxCheckBox)
 };
 
-#ifdef __VISUALC__
-    #pragma warning(pop)
-#endif
-
 #endif // _WX_CHECKBOX_H_