do not export private symbols in wx shared libraries

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58351 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/m_layout.cpp

@@ -83,9 +83,12 @@ private:
 };
 
 // Comparison routine for bsearch into an int* array of pagebreaks.
-extern "C" int wxCMPFUNC_CONV wxInteger_compare(void const* i0, void const* i1)
+extern "C"
 {
-    return *(int*)i0 - *(int*)i1;
+    static int wxCMPFUNC_CONV wxInteger_compare(void const* i0, void const* i1)
+    {
+        return *(int*)i0 - *(int*)i1;
+    }
 }
 
 bool wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak, wxArrayInt& known_pagebreaks) const