This is one of 4 packages which are still in my local overlay and which seem to be forgotten by the recent "perl-5.20" conversion: corelist suggests that perl-5.20 contains even virtual/perl-PodParser-1.620.0 for which there is not even a corresponding perl-core version in the tree. If you do not want to add this new version to the tree, I suggest that you let virtual/perl-PodParser-1.610.0 be also satisfied by perl-5.20, since it seems rather counterproductive to force users of perl-5.20 to install an older version of that package.
PodParser is still work in progress
See also https://wiki.gentoo.org/wiki/Project:Perl/Ongoing_tasks#Virtuals_that_still_need_some_attention
perl-Pod-Parser-1.620.0 (masked) added