The BLI_spin APIs use a `SpinLock` typedef whose underlying type is
contingent on the precense of `WITH_TBB`. Since our projects did not
consistently define the `WITH_TBB` definition, multiple `SpinLock` types
would end up in our final binary creating ODR violations.
Pull Request: https://projects.blender.org/blender/blender/pulls/124285
57544887d0