Fix wxUniv build with wxNO_RTTI

ForceUpperFunctor must have a default ctor when wxNO_RTTI is on, i.e.
when wxRTTI is used.

Closes #18707.

src/common/textentrycmn.cpp

@@ -341,7 +341,9 @@ namespace
 // Poor man's lambda: helper for binding ConvertToUpperCase() to the event
 struct ForceUpperFunctor
 {
-    explicit ForceUpperFunctor(wxTextEntryBase* entry)
+    // This class must have default ctor in wxNO_RTTI case, so allow creating
+    // it with null entry even if this never actually happens in practice.
+    explicit ForceUpperFunctor(wxTextEntryBase* entry = NULL)
         : m_entry(entry)
     {
     }