Arch Linux CI still seems to timeout on this test...
Note, I can't reproduce the failures in these tests on a
FreeBSD 11.1 VM while infinite-looping, even without the
"th.join(0.001)". It doesn't seem related to the use of
rb_wait_for_single_fd (r64529).
cf. https://rubyci.org/logs/rubyci.s3.amazonaws.com/arch/ruby-trunk/log/20180826T090003Z.fail.html.gz
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64543 b2dd03c8-39d4-4d8f-98ff-823fe69b080e