The reclimit system test started consistently failing on CentOS 7 [1]
and Fedora 25 [2].  In 2016, we also received a report about an
apparently identical issue on Solaris [3].  Apart from that, at least
one other failure mode was triggered in the past [4].

Failures aside, the test originally took about 10 seconds to complete
and now it needs over a minute.

[1] https://jenkins.isc.org/view/BIND/job/bind9-master-centos7-amd64-1/338/
[2] https://jenkins.isc.org/view/BIND/job/bind9-master-fedora25-amd64-1/340/
[3] https://bugs.isc.org/Ticket/Display.html?id=42382
[4] https://jenkins.isc.org/view/BIND/job/bind9-master-macmini--disable-atomic/282/