Missing define.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@31520 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/stdpaths.cpp

@@ -50,6 +50,10 @@ typedef HRESULT (WINAPI *SHGetSpecialFolderPath_t)(HWND, LPTSTR, int, BOOL);
 // used in our wxLogTrace messages
 static const wxChar *TRACE_MASK = _T("stdpaths");
 
+#ifndef CSIDL_APPDATA
+    #define CSIDL_APPDATA         0x001a
+#endif
+
 #ifndef CSIDL_LOCAL_APPDATA
     #define CSIDL_LOCAL_APPDATA   0x001c
 #endif