8 files declare their use of DenormalizerInterface in Zircon Profile 8

DenormalizableDummy.php in vendor/symfony/serializer/Tests/Fixtures/DenormalizableDummy.php

Dummy.php in vendor/symfony/serializer/Tests/Fixtures/Dummy.php

EntityNormalizer.php in core/modules/serialization/src/Normalizer/EntityNormalizer.php

Contains \Drupal\serialization\Normalizer\EntityNormalizer.

NormalizableTraversableDummy.php in vendor/symfony/serializer/Tests/Fixtures/NormalizableTraversableDummy.php

NormalizerBase.php in core/modules/hal/src/Normalizer/NormalizerBase.php

Contains \Drupal\hal\Normalizer\NormalizerBase.

ScalarDummy.php in vendor/symfony/serializer/Tests/Fixtures/ScalarDummy.php

Serializer.php in vendor/symfony/serializer/Serializer.php

TestDenormalizer.php in vendor/symfony/serializer/Tests/Normalizer/TestDenormalizer.php