Don't export sorted dynamic arrays from the shared library

This shouldn't be necessary and doing it seems to result in duplicate
symbol errors when using MSVC under some not completely elucidated
circumstances.

See https://github.com/utelle/wxpdfdoc/pull/48

Closes https://github.com/wxWidgets/wxWidgets/pull/1013

include/wx/dynarray.h

@@ -215,9 +215,11 @@ public:
 //    cannot handle types with size greater than pointer because of sorting
 // ----------------------------------------------------------------------------
 
-#define _WX_DEFINE_SORTED_TYPEARRAY_2(T, name, base, defcomp, classexp)       \
+// Note that "classdecl" here is intentionally not used because this class has
+// only inline methods and so never needs to be exported from a DLL.
+#define _WX_DEFINE_SORTED_TYPEARRAY_2(T, name, base, defcomp, classdecl)      \
     typedef wxBaseSortedArray<T> wxBaseSortedArrayFor##name;                  \
-    classexp name : public wxBaseSortedArrayFor##name                         \
+    class name : public wxBaseSortedArrayFor##name                            \
     {                                                                         \
     public:                                                                   \
         name(wxBaseSortedArrayFor##name::SCMPFUNC fn defcomp)                 \