Fix system tests on Windows after merging libuv work

Merging !2528 (merged) broke a significant number of system tests on Windows.

In Jenkins, the following tests failed (I only performed one run so far):

• autosign
• digdelv
• dnssec
• keepalive
• legacy
• mirror
• mkeys
• nsupdate
• padding
• pipelined
• rpz
• rrl
• statistics
• stub
• synthfromdnssec
• tkey
• upforwd
• wildcard
• zero

See: https://jenkins.isc.org/view/BIND_Parameterized/job/bind9-parameterized-win2012-x64/353/console

I also did one test run in GitLab CI¹ and the failed tests were those listed above + the pending system test.

Some notes:

• The zero system test alone takes some 15-20 minutes to complete on Windows. I recall having issues with this test when I was first trying to add Windows to GitLab CI. From what I recall, the issue was that a significant number of queries are sent during that test and Windows is just unable to keep up with logging at -d 99. I initially worked around it by putting named.args files in place that did not include -d 99 because all those logs are not really needed in that test. However, I eventually came up with a different fix (!2398 (merged)) that seemed to be good enough until now. Perhaps decreasing logging verbosity is what we will need in the end? I have not yet investigated why that test takes so long to complete with current master.

• In the nsupdate test, named hangs in weird ways - both in Jenkins and GitLab CI, I had to "intervene" by killing binaries manually or else the test was stuck. FWIW, I have not yet tried running that test on its own, it was always run as part of the whole test suite.

While we can skip a single development release on Windows, releasing BIND 9.16.0 will require sorting all these issues out.

1. !2556 (merged) is a prerequisite for any system test to work in GitLab CI ↩