Fix the remaining issues that broke the PLT check

Add internal API for the default button box layouts to so we don't
need to call deprectated GTK+ functions (which are invisible with
GTK_DISABLE_DEPRECATED).

gtk/gtkbbox.c

@@ -493,9 +493,9 @@ gtk_button_box_kludge_get_layout_default (GtkButtonBox *widget)
   orientation = gtk_orientable_get_orientation (GTK_ORIENTABLE (widget));
 
   if (orientation == GTK_ORIENTATION_HORIZONTAL)
-    return gtk_hbutton_box_get_layout_default ();
+    return _gtk_hbutton_box_get_layout_default ();
   else
-    return gtk_vbutton_box_get_layout_default ();
+    return _gtk_vbutton_box_get_layout_default ();
 }
 
 static void

gtk/gtkhbbox.c

@@ -92,5 +92,11 @@ gtk_hbutton_box_get_layout_default (void)
   return default_layout_style;
 }
 
+GtkButtonBoxStyle
+_gtk_hbutton_box_get_layout_default (void)
+{
+  return default_layout_style;
+}
+
 #define __GTK_HBUTTON_BOX_C__
 #include "gtkaliasdef.c"

gtk/gtkhbbox.h

@@ -72,6 +72,9 @@ void gtk_hbutton_box_set_spacing_default (gint spacing);
 void gtk_hbutton_box_set_layout_default (GtkButtonBoxStyle layout);
 #endif
 
+/* private API */
+GtkButtonBoxStyle _gtk_hbutton_box_get_layout_default (void);
+
 G_END_DECLS
 
 #endif /* __GTK_HBUTTON_BOX_H__ */

gtk/gtkvbbox.c

@@ -94,5 +94,12 @@ gtk_vbutton_box_get_layout_default (void)
   return default_layout_style;
 }
 
+GtkButtonBoxStyle
+_gtk_vbutton_box_get_layout_default (void)
+{
+  return default_layout_style;
+}
+
+
 #define __GTK_VBBOX_C__
 #include "gtkaliasdef.c"

gtk/gtkvbbox.h

@@ -73,6 +73,8 @@ GtkButtonBoxStyle gtk_vbutton_box_get_layout_default (void);
 void gtk_vbutton_box_set_layout_default (GtkButtonBoxStyle layout);
 #endif
 
+/* private API */
+GtkButtonBoxStyle _gtk_vbutton_box_get_layout_default (void);
 
 G_END_DECLS