Uh let's try that YIELD thing once more ... we want to yield in such a way

that if the mutex is broken then it'll definately show up as an error.
It's amazing how doing this yield flattens out differences between the
various options.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79548 13f79535-47bb-0310-9956-ffa450edef68