message: Enable a Session tests using function and set_device
  These tests were disabled for C API because those features
  were not implemented. They are now.
diff: @@ -1583,7 +1583,6 @@ class SessionTest(test_util.TensorFlowTestCase):
  sess.run(enqueue_op)
  self.assertEqual(sess.run(q.size()), num_epochs * 2)
  - @test_util.disable_c_api # set_device does not work with C API
  def testRegisterFetchAndFeedConversionFunctions(self):
  class SquaredTensor(object):
  def __init__(self, tensor):
  @@ -1733,11 +1732,9 @@ class SessionTest(test_util.TensorFlowTestCase):
  result = sess.run(f)
  self.assertEqual(result, 2.0)
  - @test_util.disable_c_api # functions don't work with C API
  def testAddFunctionToSession(self):
  self.runTestAddFunctionToSession()
  - @test_util.disable_c_api # functions don't work with C API
  def testAddFunctionToGrpcSession(self):
  server = server_lib.Server.create_local_server()
  self.runTestAddFunctionToSession(server.target)
  