Added wxGCDC(wxEnhMetaFileDC) ctor too.

Make it possible to create wxGCDC associated with a metafile DC in wxMSW too.

Closes #13326.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@68304 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/dcgraph.h

@@ -35,6 +35,17 @@ public:
     */
     wxGCDC( const wxPrinterDC& dc );
 
+    /**
+       Constructs a wxGCDC from a wxEnhMetaFileDC.
+
+       This constructor is only available in wxMSW port and when @c
+       wxUSE_ENH_METAFILE build option is enabled, i.e. when wxEnhMetaFileDC
+       class itself is available.
+
+       @since 2.9.3
+    */
+    wxGCDC( const wxEnhMetaFileDC& dc );
+
     /**
        Retrieves associated wxGraphicsContext
     */