This operation holds a replicated input to a `tpu.replicate()` computation subgraph.
Each replicated input has the same shape and type alongside the output.

For example:
```
%a = "tf.opA"()
%b = "tf.opB"()
%replicated_input = "tf.TPUReplicatedInput"(%a, %b)
%computation = "tf.Computation"(%replicated_input)
```
The above computation has a replicated input of two replicas.
  }];