Issue #3088369 by mikelutz, alexpott, Berdir, Gábor Hojtsy, andypost, martin107, greg.1.anderson, dawehner, jibran, Wim Leers, Mile23, catch: Update Drupal 9 to Symfony 4.4-dev

Issue #3079791 by mikelutz, shaal, Wim Leers, hussainweb, xjm, catch, Charlie ChX Negyesi, Mixologic, Gábor Hojtsy, heddn, amateescu: Bump Drupal's minimum PHP version to 7.2 as soon as 9.0.x is branched (a higher version may be required later)

Issue #3053363 by alexpott, Wim Leers, Berdir, mondrake, xjm: Remove support for PHP 5 in Drupal 8.8

Issue #2867960 by Eric_A, Mile23, Jo Fitzgerald, mpdonadio: Merge Component composer.json files to account for them during build

Issue #2935137 by el7cosmos, Mixologic: License "GPL-2.0+" is a deprecated SPDX license identifier, use "GPL-2.0+-only" or "GPL-2.0+-or-later" instead

This reverts commit 7c486399.

Issue #2747083 by Eric_A, Mile23, alexpott: drupal/core-dependency-injection wrongly requires symfony/expression-language

Issue #2744357 by rajeshwari10, pashupathi nath gajawada, chishah92, Eric_A: drupal/core-* components Symfony requirements conflict with drupal/core

Issue #2337283 by hussainweb, Mile23, alexpott, aleksip, dawehner, heykarthikwithu, naveenvalecha, Crell, xjm, davidwbarratt, Fabianx, jhedstrom, tim.plunkett, larowlan, tstoeckler: Add a composer.json file to every component

Issue #2497243 by Fabianx, znerol, fgm, Wim Leers, darol100, jhedstrom, hussainweb, pfrenssen, neclimdul, jibran, Nitesh Sethia, dawehner, chx, catch, benjy, Aki Tendo: Replace Symfony container with a Drupal one, stored in cache