10 files declare their use of ComplexDataInterface in Zircon Profile 8.0

AllowedValuesConstraintValidator.php in core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/AllowedValuesConstraintValidator.php

Contains \Drupal\Core\Validation\Plugin\Validation\Constraint\AllowedValuesConstraintValidator.

ComplexDataConstraintValidator.php in core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/ComplexDataConstraintValidator.php

Contains \Drupal\Core\Validation\Plugin\Validation\Constraint\ComplexDataConstraintValidator.

ComplexDataNormalizerTest.php in core/modules/serialization/tests/src/Unit/Normalizer/ComplexDataNormalizerTest.php

Contains \Drupal\Tests\serialization\Unit\Normalizer\ComplexDataNormalizerTest.

EntityAdapter.php in core/lib/Drupal/Core/Entity/Plugin/DataType/EntityAdapter.php

Contains \Drupal\Core\Entity\Plugin\DataType\EntityAdapter.

FieldItemInterface.php in core/lib/Drupal/Core/Field/FieldItemInterface.php

Contains \Drupal\Core\Field\FieldItemInterface.

IsNullConstraintValidator.php in core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/IsNullConstraintValidator.php

Contains \Drupal\Core\Validation\Plugin\Validation\Constraint\IsNullConstraintValidator.

ItemList.php in core/lib/Drupal/Core/TypedData/Plugin/DataType/ItemList.php

Contains \Drupal\Core\TypedData\Plugin\DataType\ItemList.

Map.php in core/lib/Drupal/Core/TypedData/Plugin/DataType/Map.php

Contains \Drupal\Core\TypedData\Plugin\DataType\Map.

NotNullConstraintValidator.php in core/lib/Drupal/Core/Validation/Plugin/Validation/Constraint/NotNullConstraintValidator.php

Contains \Drupal\Core\Validation\Plugin\Validation\Constraint\NotNullConstraintValidator.

RecursiveContextualValidator.php in core/lib/Drupal/Core/TypedData/Validation/RecursiveContextualValidator.php

Contains \Drupal\Core\TypedData\Validation\RecursiveContextualValidator.