Issue #3436255 by mondrake, longwave: Fix return typehinting for Compiler and EventSubscriber related classes

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2719695 by alexpott, Mile23: Fix 'Drupal.Classes.ClassDeclaration.CloseBraceAfterBody' coding standard

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2248767 by effulgentsia, beejeebus, alexpott: Use fast, local cache back-end (APCu, if available) for low-write caches (bootstrap, discovery, and config).

Issue #1764474 by Berdir, chx, alexpott, pounard, msonnabaum: Make Cache interface and backends use the DIC.