PERL5_PACKLIST and .orig files

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

If pkgsrc patches a Perl Module, the resulting .orig file ends up in the
.packlist and, via PERL5_PACKLIST, in the PLIST, so is contained in the
package.
See devel/p5-Proc-Daemon for an example.

Is this an error in the PERL5_PACKLIST handling code or is a package's
Makefile supposed to remove the .orig files post-patch?