Add small helper function to wxMSW wxToolBar code

Encapsulate the logic for deciding whether we should show the labels for
the embedded controls or not in a small helper function, to make it
simpler to change it in the future if needed and also to have a single
place to explain why do we do what we do now.

No real changes.

include/wx/msw/toolbar.h

@@ -174,6 +174,16 @@ private:
     WXHBRUSH MSWGetToolbarBgBrush();
 #endif // wxHAS_MSW_BACKGROUND_ERASE_HOOK
 
+    // Return true if we're showing the labels for the embedded controls: we
+    // only do it if text is enabled and, somewhat less expectedly, if icons
+    // are enabled too because showing both the control and its label when only
+    // text is shown for the other buttons is too inconsistent to be useful.
+    bool AreControlLabelsShown() const
+    {
+        return HasFlag(wxTB_TEXT) && !HasFlag(wxTB_NOICONS);
+    }
+
+
     wxDECLARE_EVENT_TABLE();
     wxDECLARE_DYNAMIC_CLASS(wxToolBar);
     wxDECLARE_NO_COPY_CLASS(wxToolBar);