Spurious wakeup is unavoidable with MJIT; and any real
code must be able to deal with spurious wakeup anyways.
[ruby-core:87882] https://bugs.ruby-lang.org/issues/14901
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64005 b2dd03c8-39d4-4d8f-98ff-823fe69b080e