Issue #2433281 by neclimdul, mrjmd: Move Role Constants on to a Class/Interface

core/includes/bootstrap.inc

core/lib/Drupal/Core/Session/AccountInterface.php

core/lib/Drupal/Core/Session/SessionHandler.php

core/lib/Drupal/Core/Session/UserSession.php

core/modules/aggregator/src/Tests/FeedCacheTagsTest.php

core/modules/aggregator/src/Tests/ItemCacheTagsTest.php

core/modules/block/src/Tests/BlockTest.php

core/modules/book/src/Tests/BookTest.php

core/modules/comment/comment.module

core/modules/comment/src/CommentManager.php

core/modules/comment/src/Tests/CommentAdminTest.php

core/modules/comment/src/Tests/CommentAnonymousTest.php

core/modules/comment/src/Tests/CommentBlockTest.php

core/modules/comment/src/Tests/CommentCSSTest.php

core/modules/comment/src/Tests/CommentCacheTagsTest.php

core/modules/comment/src/Tests/CommentFieldAccessTest.php

core/modules/comment/src/Tests/CommentInterfaceTest.php

core/modules/comment/src/Tests/CommentLinksTest.php

core/modules/comment/src/Tests/CommentNonNodeTest.php

core/modules/comment/src/Tests/CommentStatisticsTest.php