Avoid gcc -Wunused-function warnings in wxEvtHandler unit test

The warnings are justified as the functions defined by the event table
macros are indeed not used here because we only write them to test that
they compile, but not useful, so suppress them.

tests/events/evthandler.cpp

@@ -127,6 +127,11 @@ private:
     wxDECLARE_EVENT_TABLE();
 };
 
+// Avoid gcc warning about some of the functions defined by the expansion of
+// the event table macros being unused: they are indeed unused, but we still
+// want to have them to check that they compile.
+wxGCC_WARNING_SUPPRESS(unused-function)
+
 wxBEGIN_EVENT_TABLE(MyClassWithEventTable, wxEvtHandler)
     EVT_IDLE(MyClassWithEventTable::OnIdle)
 
@@ -138,6 +143,8 @@ wxBEGIN_EVENT_TABLE(MyClassWithEventTable, wxEvtHandler)
     //EVT_IDLE(MyClassWithEventTable::OnAnotherEvent)
 wxEND_EVENT_TABLE()
 
+wxGCC_WARNING_RESTORE(unused-function)
+
 } // anonymous namespace