jetm [1] filed a orphan request for java8-openjdk [2]:

Javier,
The maintainer is gone. He has not been updated all its packages more
than a year ago. Please put Orphan these packages, so other people can
adopt it.

Thanks,
Javier

[1] https://aur.archlinux.org/account/jetm/
[2] https://aur.archlinux.org/pkgbase/java8-openjdk/