This reverts commit a70d8cf6.

Issue #3040210 by Spokje, phenaproxima, shaal, lauriii, hctom, a.dmitriiev, xjm, cilefen, eelkeblok: Updating twig/twig to v1.38.2 (included in Drupal 8.6.11) causes fatal error when embed tags are used in templates

(cherry picked from commit ea91981e)

Issue #3037970 by Berdir, Baysaa: Custom serialized field's data should be normalized even if it's empty

Issue #3039408 by vijaycs85, WidgetsBurritos, alexpott, phenaproxima, Joseph Zhao, tstoeckler, kfritsche, mikelutz, fabpot: Updating twig/twig to v1.38.0 or v1.38.1 causes fatal error

Issue #3028490 by tim.plunkett, Kristen Pol, xjm, tedbow, r.aubin, phenaproxima: Users with "configure any layout" can see entities they don't have "view" access to

SA-CORE-2019-003 by samuel.mortenson, Berdir, pwolanin, dawehner, cashwilliams, Wim Leers, xjm, larowlan, alexpott, plach, damiankloip, tstoeckler, tedbow, DamienMcKenna, effulgentsia, RobLoach, gabesullice, drumm, heshanlk, dsnopek, fago, miro_dietiker, truls1502

(cherry picked from commit b0a63891)

Issue #3026386 by dsnopek, samuel.mortenson, xjm, ydahi, alexpott, Fabianx, kferencz91, littlepixiez, greggles, cilefen: Drush fatal error after upgrading to 8.6.6, 8.5.9, or 7.62: PHP Fatal error:  Uncaught TYPO3PharStreamWrapperException

SA-CORE-2019-002 by greggles, cashwilliams, EclipseGc, larowlan, samuel.mortenson, alexpott, tedbow, effulgentsia, Fabianx, xjm, mlhess

SA-CORE-2018-006 by alexpott, attilatilman, bkosborne, catch, bonus, Wim Leers, Sam152, Berdir, Damien Tournoud, Dave Reid, Kova101, David_Rothstein, dawehner, dsnopek, samuel.mortenson, stefan.r, tedbow, xjm, timmillwood, pwolanin, njbooher, dyates, effulgentsia, klausi, mlhess, larowlan