This reverts commit ae8be3cc.

Issue #2001206 by andypost, penyaskito, herom, Crell, ebeyrent, DmitryDrozdik: Replace drupal_container() with Drupal::service().

Issue #1203886 by catch, sun, David_Rothstein, RobLoach, tim.plunkett, greggles, alexpott, DamienMcKenna: Remove the PHP module from Drupal core

Issue #1827112 by alexpott, vijaycs85, dawehner, cspitzlay, cam8001: Convert 'install_profile()' variable to Settings.

Issue #1911190 by mitron: Test that drupal_get_filename() has NULL return value when the file is not found.

Revert "Revert the revert of Issue #1849004 by chx, xjm: One Service Container To Rule Them All. It was innocent after all."

This reverts commit a1638b87.

This reverts commit 761ac679.

Issue #1808200 by sun: Fixed Unit test performance significantly decreased since system list config conversion.

Issue #1431658 by Albert Volkman, xjm, kid_icarus, ChinggizKhan, rgristroph, connork: Massive API docs cleanup for system tests

Issue #562042 by cburschka, Rob Loach, sun, scor: Added Search for install profiles in sites/[all|site]/profiles folders, and move core profiles into /core/profiles.