Sprite masks not working on sprites using a GPU-instanced material

Steps to reproduce:
- Create a sprite mask
- Create a new material using the "Sprites/Default" shader and enable "GPU instancing"
- Create a sprite using the material from the previous step.
- Set the sprite mask interaction to anything other than "None".

Using this step, the sprite will ignore the mask. It works by disabling "GPU instancing" on the material.