7 files declare their use of Select in Drupal 8

CachePluginBase.php in core/modules/views/src/Plugin/views/cache/CachePluginBase.php

DatabaseLegacyTest.php in core/tests/Drupal/KernelTests/Core/Database/DatabaseLegacyTest.php

OrderByTest.php in core/tests/Drupal/Tests/Core/Database/OrderByTest.php

PagerPluginBaseTest.php in core/modules/views/tests/src/Unit/Plugin/pager/PagerPluginBaseTest.php

Contains \Drupal\Tests\views\Unit\Plugin\pager\PagerPluginBaseTest.

Select.php in core/lib/Drupal/Core/Database/Driver/sqlite/Select.php

Select.php in core/lib/Drupal/Core/Database/Driver/pgsql/Select.php

Select.php in core/lib/Drupal/Core/Database/Driver/mysql/Select.php