demos: Ignore deprecations

Most of these demos should be ported to use
global style providers eventually. For now,
just ignore the deprecations.

demos/gtk-demo/css_basics.c

@@ -6,6 +6,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,

demos/gtk-demo/css_pixbufs.c

@@ -7,6 +7,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,

demos/gtk-demo/css_shadows.c

@@ -5,6 +5,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static void
 show_parsing_error (GtkCssProvider *provider,
                     GtkCssSection  *section,

demos/gtk-demo/dnd.c

@@ -11,6 +11,8 @@
 
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 G_DECLARE_FINAL_TYPE (CanvasItem, canvas_item, CANVAS, ITEM, GtkWidget)
 
 struct _CanvasItem {

demos/gtk-demo/gltransition.c

@@ -20,6 +20,8 @@
 #include "gtkshadertoy.h"
 #include "gskshaderpaintable.h"
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 static GtkWidget *demo_window = NULL;
 
 static void

demos/gtk-demo/listview_ucd.c

@@ -10,6 +10,7 @@
 #include "script-names.h"
 #include "unicode-names.h"
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 
 #define UCD_TYPE_ITEM (ucd_item_get_type ())
 G_DECLARE_FINAL_TYPE (UcdItem, ucd_item, UCD, ITEM, GObject)

demos/gtk-demo/peg_solitaire.c

@@ -8,6 +8,8 @@
 #include "config.h"
 #include <gtk/gtk.h>
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
+
 /* Create an object for the pegs that get moved around in the game.
  *
  * We implement the GdkPaintable interface for them, so we can use GtkPicture