Merge r1543056 from trunk:

Follow up to r1543033:

Use the new code required for OS X/Darwin on the other platforms too.
(IOW, we're willing to peek in the socket as long as APR_POLLIN is
returned, regardless of other flags.)

Submitted by: trawick
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/branches/1.5.x@1543057 13f79535-47bb-0310-9956-ffa450edef68