mark all dtors which are virtual because base class dtor is virtual explicitly virtual themselves

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41020 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/os2/dc.h

@@ -84,7 +84,7 @@ public:
     wxDCCacheEntry( HPS   hPS
                    ,int   nDepth
                   );
-    ~wxDCCacheEntry();
+    virtual ~wxDCCacheEntry();
 
     WXHBITMAP                       m_hBitmap;
     HPS                             m_hPS;
@@ -100,7 +100,7 @@ class WXDLLEXPORT wxDC : public wxDCBase
 
 public:
     wxDC(void);
-    ~wxDC();
+    virtual ~wxDC();
 
     // implement base class pure virtuals
     // ----------------------------------