Currently, there are quite a lot of special cases that are not needed anymore.
Status as of 2019-12-05:
- Mention in composer.lock from sebastian/environment which should go away in future when we bump PHPUnit.
- Mentions in the upstream mongofill package used by Performance.
- Documentation mention in 404.php and README which can be updated (but to what?).
- Documentation mention in ServiceConfig.php of hhvm-fatal-error.php which has been… removed now?
- Used in arclamp.php which presumably is also used by PHP72?
Documention mention in profiler.php abouse historical uses, and can stay.