To implement waiting for an arbitrary number of handles, we group them
in buckets up to (MAXIMUM_WAIT_OBJECTS - 1) objects, and then assign a
dedicated wait queue thread. The last handle is used to notify about
changes.

Also lock/unlock the module only on creation/destruction of the object.

Also lock/unlock the module only on creation/destruction of the object.

Also lock/unlock the module only on creation/destruction of the object.

Also lock/unlock the module only on creation/destruction of the object.

Also lock/unlock the module only on creation/destruction of the object.

That can only happen by manually modifying
select_vertex_implementation() and select_fragment_implementation(),
which may be useful for testing non-default vertex / fragment pipeline
implementations.