[perl #92436] Filter::Simple can’t find end of POD

[perl #92436] Filter::Simple can’t find end of POD

Filter::Simple’s $pod_or_DATA regexp was mistakenly written to look
for =end if the pod section began with =begin, and to look for the
end of the paragraph if the pod began with =for.  Only =cut and EOF
can end pod.

This patch does not fix Filter::Simple’s naïve way of finding the
beginning of pod.