When GPU subdivision is used, and the modifier is not set to be applied
on the cage, UV selection is not synced with the face selection in the
viewport.
This happens because the extraction, despite being in edit mode, is set
to `MESH` instead of `BMESH` (or `MAPPED` in some cases) like for CPU
subdivision, and since the mesh is not always synchrnised with the BMesh
the edit mode flags are not always updated.
With GPU subdivision, when creating the `MeshRenderData`, the condition
`has_mdata && do_final && editmesh_eval_final != editmesh_eval_cage` is
true which forces the `MESH` extraction. Following comment in D14485,
this replace the `has_mdata` in the condition with `use_mapped` which
solves the issue.
Differential Revision: https://developer.blender.org/D15248
6c3965c027