Merge branch 'PHP-7.4'

* PHP-7.4:
  Turn system_id into a true global

diff --cc ext/opcache/ZendAccelerator.c
Simple merge

diff --cc ext/opcache/ZendAccelerator.h
Simple merge

diff --cc ext/opcache/shared_alloc_win32.c
Simple merge

diff --cc ext/opcache/zend_file_cache.c
Simple merge