[gtk/glshader-paintable: 2/4] Work around linker problems

[Matthias Clasen <matthiasc src gnome org>]

commit e1599fe6bc06d2fcbd4e0cecb231cf2b41aa7d14
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Sep 25 00:22:01 2020 -0400

    Work around linker problems
    
    Unless a symbol from gskshaderpaintable.c is used
    in libgtk.so, none of its symbols survive in the
    final so. Linkers are evil.

 gtk/gtkwidget.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index f9d5f079f9..bf0b814097 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -736,6 +736,8 @@ gtk_widget_base_class_init (gpointer g_class)
   GtkWidgetClass *klass = g_class;
   GtkWidgetClassPrivate *priv;
 
+  g_type_ensure (GSK_TYPE_SHADER_PAINTABLE);
+
   priv = klass->priv = G_TYPE_CLASS_GET_PRIVATE (g_class, GTK_TYPE_WIDGET, GtkWidgetClassPrivate);
   
   priv->template = NULL;