IndexAllocators deprecated?

[Anjiang-Wei]

The code comments in the examples touch upon IndexAllocators several times. E.g., https://github.com/StanfordLegion/legion-manual/blob/master/Examples/Regions/logicalregions/logicalregions.cc#L33

// Clean up.  IndexAllocators and FieldAllocators automatically have their resources reclaimed
  // when they go out of scope.
  runtime->destroy_logical_region(ctx,lr1);
  runtime->destroy_logical_region(ctx,lr2);
  runtime->destroy_field_space(ctx,fs);
  runtime->destroy_index_space(ctx,is);

However, according to legion.h, IndexAllocators is a deprecated class:
https://github.com/StanfordLegion/legion/blob/stable/runtime/legion.h#L412-L429

/**
     * \class IndexAllocator
     * @deprecated
     * Index allocators provide objects for doing allocation on
     * index spaces.  They must be explicitly created by the
     * runtime so that they can be linked back to the runtime.
     * Index allocators can be passed by value to functions
     * and stored in data structures, but should not escape 
     * the enclosing context in which they were created.
     *
     * Index space allocators operate on a single index space
     * which is immutable.  Separate index space allocators
     * must be made to perform allocations on different index
     * spaces.
     *
     * @see Runtime
     */
    class LEGION_DEPRECATED("Dynamic IndexAllocators are no longer supported")

https://github.com/StanfordLegion/legion/blob/stable/runtime/legion.h#L6607-L6619

      /**
       * @deprecated
       * Create an index allocator object for a given index space
       * This method is deprecated becasue index spaces no longer support
       * dynamic allocation. This will still work only if there is exactly
       * one allocator made for the index space throughout the duration
       * of its lifetime.
       * @param ctx enclosing task context
       * @param handle for the index space to create an allocator
       * @return a new index space allocator for the given index space
       */
      LEGION_DEPRECATED("Dynamic index allocation is no longer supported.")
      IndexAllocator create_index_allocator(Context ctx, IndexSpace handle);

[elliottslaughter]

Yes, we should remove IndexAlloacator if it's being used in the manual. Not only is it deprecated, I don't think it has ever worked in a sane way.