xla

1a7a07b7 - Revert "Revert "Add `ReduceScatter` XLA collective"" (#3166)

Revert "Revert "Add `ReduceScatter` XLA collective"" (#3166) * Revert "Revert "Add `AllReduceScatter` XLA collective op (#3075)" (#3088)" This reverts commit e93451614401d6a53b50ae119dc4ccdceb09a207. * Update hash function to match master