When more than one, consecutive, subdivision modifier is used on a Mesh,
the last subsurf modifier is used for GPU subdivision even though it
might be disabled. This is because retrieving the last subsurf modifier
in the draw code did not check whether the modifier was disabled or not.
To fix this, the session UUID of the modifier which delegated evaluation
to the GPU code is cached and used in the draw to select the right subsurf
modifier.
Differential Revision: https://developer.blender.org/D14488
68ca12a7fc