is is_writeable_ACLSafe() still a thing?

Hello,

having to check for some .tmp and .tmp.gz leftovers under cache directory, I came across this `is_writeable_ACLSafe` function. Its phpdoc says it was taken from the page at [is_writable()](https://www.php.net/is_writable) from a **legolas558** guy.

Now I see the 13 years old note has been down voted several times, maybe it's random, I don'tknow, but there are better suggestions there.

Could it be it would be better to check and improve the function?

Locate is_writeable_ACLSafe() and review its PHPDoc and callers related to cache .tmp and .tmp.gz leftovers. Compare the current behavior with the referenced is_writable() guidance and project compatibility needs; done requires an agreed change or decision to retain it, but no file or test is named in the issue.

Written by the indexing model from the issue text.