message: Fix missing imports popdist_strategy
  Reviewers: #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, frederikm
  Maniphest Tasks: T67994
diff: @@ -21,6 +21,7 @@ from tensorflow.python.distribute import cross_device_ops as cross_device_ops_li
  from tensorflow.python.distribute import device_util
  from tensorflow.python.distribute import distribute_lib
  from tensorflow.python.distribute import distribute_utils
  +from tensorflow.python.distribute import numpy_dataset
  from tensorflow.python.distribute import reduce_util
  from tensorflow.python.distribute import values
  from tensorflow.python.framework import device as device_lib
  @@ -34,7 +35,6 @@ from tensorflow.python.ops import control_flow_ops
  from tensorflow.python.ops import variable_scope
  from tensorflow.python.training import server_lib
  from tensorflow.python.training.tracking import base as trackable
  -from tensorflow.python.util import tf_contextlib
  from tensorflow.python.ipu.horovod import Sum, Average, \
  allreduce as hvd_allreduce, \
  broadcast as hvd_broadcast
  @@ -106,25 +106,6 @@ class PopDistStrategy(distribute_lib.StrategyV1,
  return True
  -def _is_inside_compilation():
  - graph = ops.get_default_graph()
  - attrs = graph._attr_scope_map # pylint: disable=protected-access
  -
  - is_in_xla_context = control_flow_util.GraphOrParentsInXlaContext(graph)
  - is_outside_compilation = scopes.OUTSIDE_COMPILATION_NAME in attrs
  -
  - return is_in_xla_context and not is_outside_compilation
  -
  -
  -@tf_contextlib.contextmanager
  -def _outside_compilation_scope_if_needed(name):
  - if _is_inside_compilation():
  - with scopes.outside_compilation_scope(name):
  - yield
  - else:
  - yield
  -
  -
  def _ipu_device_for_host(ipu_device_string, host_device_string):
  ipu_device = device_lib.DeviceSpec.from_string(ipu_device_string)
  host_device = device_lib.DeviceSpec.from_string(host_device_string)
  @@ -139,11 +120,6 @@ def _ipu_device_for_host(ipu_device_string, host_device_string):
  return ipu_for_host.to_string()
  -def _make_identity_op(v):
  - name = v.name.replace(":", "_")
  - return array_ops.identity(v, name=name)
  -
  -
  class IPUDistributedVariable(values.DistributedVariable): # pylint: disable=abstract-method
  pass
  