Remove _clutter_shader_release_all()

This function is called when the backend is being disposed - as a way
of releasing all ClutterShader. This doesn't take into account three
things:

  - ClutterShader is deprecated
  - the Backend is *never* disposed
  - once the process terminates, all its resources are automatically
    released by the OS

So the _clutter_shader_release_all() function is a pointless exercise
in futility.

clutter/deprecated/clutter-shader.c

@@ -819,20 +819,6 @@ clutter_shader_set_uniform (ClutterShader *shader,
     g_assert_not_reached ();
 }
 
-/*
- * _clutter_shader_release_all:
- *
- * Iterate through all #ClutterShaders and tell them to release GL context
- * related sources.
- */
-void
-_clutter_shader_release_all (void)
-{
-  g_list_foreach (clutter_shaders_list,
-                  (GFunc) clutter_shader_release,
-                  NULL);
-}
-
 /**
  * clutter_shader_get_fragment_source:
  * @shader: a #ClutterShader

clutter/deprecated/clutter-shader.h

@@ -139,9 +139,6 @@ CoglHandle            clutter_shader_get_cogl_program         (ClutterShader
 CoglHandle            clutter_shader_get_cogl_fragment_shader (ClutterShader      *shader);
 CoglHandle            clutter_shader_get_cogl_vertex_shader   (ClutterShader      *shader);
 
-/* private */
-void                  _clutter_shader_release_all        (void);
-
 #endif /* CLUTTER_DISABLE_DEPRECATED */
 
 G_END_DECLS

clutter/osx/clutter-backend-osx.c

@@ -228,8 +228,6 @@ clutter_backend_osx_dispose (GObject *object)
 {
   ClutterBackendOSX *self = CLUTTER_BACKEND_OSX (object);
 
-  _clutter_shader_release_all ();
-
   [self->context release];
   self->context = NULL;
 

clutter/win32/clutter-backend-win32.c

@@ -146,9 +146,6 @@ clutter_backend_win32_dispose (GObject *gobject)
   CLUTTER_NOTE (BACKEND, "Removing the event source");
   _clutter_backend_win32_events_uninit (CLUTTER_BACKEND (backend_win32));
 
-  /* Unrealize all shaders, since the GL context is going away */
-  _clutter_shader_release_all ();
-
   G_OBJECT_CLASS (clutter_backend_win32_parent_class)->dispose (gobject);
 
   if (backend->cogl_context)