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

Issue #3032078 by jrglasgow, dagomar, Berdir, nikitagupta, catch, anmolgoyal74, technoveltyco, idebr, ndf, jonas139, nod_: Multiple webheads can cause infinite growth of Twig cache

Issue #2937888 by dhruveshdtripathi, idebr, RoSk0, mohit1604, mfernea, borisson_: Fix 'Drupal.Commenting.DocComment.LongNotCapital' coding standard

Issue #2569119 by pwolanin, marvin_B8, jhedstrom, csheltonlcm, alexpott, dawehner, Fabianx, catch:  Use Crypt::hashBase64(), not hash('crc32b') or sha1 for placeholder tokens

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

Issue #2544932 by dawehner, Fabianx, Wim Leers, Gábor Hojtsy, alexpott, catch, chx, msonnabaum: Twig should not rely on loading php from shared file system