// Tests loop with resource that is unique per iteration.
//
// In cases where a resource-allocating op creates a new unique resource per
// loop iteration (ops with `TF_UniqueResourceAllocation` trait, in this case:
// `tf.StackV2`), make sure that we don't create data dependencies between
// different iterations for such resources. This is in line with the behavior
// for the same loop unrolled. In this particular case, no data chain and token

      "SpaceToBatch",
      "SpaceToBatchND",
      "SpaceToDepth",
      "SparseMatMul",
      "SparseToDense",
      "StackCloseV2",
      "StackPopV2",
      "StackPushV2",
      "StackV2",
      "StatefulPartitionedCall",
      "StatefulStandardNormalV2",
      "StatefulTruncatedNormal",
      "StatefulUniform",
      "StatefulUniformFullInt",
      "StatefulUniformInt",

maximum size needs to be a constant and 2) a push op can be found with a
known shape, and all push ops need to have the same shape.

A stack creation op "tf.StackV2" will be turned in to two zero-initialized
variables, for the buffer and current size. Each push will be turned into
```mlir
  %old_val = "tf.ReadVariableOp"(%buffer)
  %old_size = "tf.ReadVariableOp"(%size)