Shadow mapping render pass (#11244)

Co-authored-by: x2048 <codeforsmile@gmail.com>

src/client/wieldmesh.h

@@ -27,6 +27,7 @@ struct ItemStack;
 class Client;
 class ITextureSource;
 struct ContentFeatures;
+class ShadowRenderer;
 
 /*!
  * Holds color information of an item mesh's buffer.
@@ -124,6 +125,8 @@ private:
 	// so this variable is just required so we can implement
 	// getBoundingBox() and is set to an empty box.
 	aabb3f m_bounding_box;
+
+	ShadowRenderer *m_shadow;
 };
 
 void getItemMesh(Client *client, const ItemStack &item, ItemMesh *result);