Fix core Perl module Module::Pluggable such that it can find plugins that live
in symlinked directories.

Patch borrowed/adapted from Nixpkgs.

--- perl-5.16.1/cpan/Module-Pluggable/lib/Module/Pluggable/Object.pm	2015-04-08 23:28:48.120164135 -0500
+++ perl-5.16.1/cpan/Module-Pluggable/lib/Module/Pluggable/Object.pm	2015-04-08 23:30:27.032166704 -0500
@@ -164,7 +164,7 @@
         my $sp = catdir($dir, (split /::/, $searchpath));
 
         # if it doesn't exist or it's not a dir then skip it
-        next unless ( -e $sp && -d _ ); # Use the cached stat the second time
+        next unless ( -e $sp );
 
         my @files = $self->find_files($sp);
 
@@ -279,7 +279,7 @@
                              (my $path = $File::Find::name) =~ s#^\\./##;
                              push @files, $path;
                            }
-                      }, $search_path );
+                      }, "$search_path/." );
     }
     #chdir $cwd;
     return @files;
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<div class='path'>path: <a href='/guix/log/?id=b3e0a973bca6fe5de7356f3d70c4b7d468b0a759'>root</a>/<a href='/guix/log/CODE-OF-CONDUCT?id=b3e0a973bca6fe5de7356f3d70c4b7d468b0a759'>CODE-OF-CONDUCT</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/CODE-OF-CONDUCT?id=b3e0a973bca6fe5de7356f3d70c4b7d468b0a759&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-03-01 13:18:01 -0500'>2022-03-01</span></td><td><a href='/guix/commit/CODE-OF-CONDUCT?id=c67912011154e2b347cdf6f3e633e87fd44f409c'>CODE-OF-CONDUCT: Add a top notice.</a><span class='msg-avail'>...<span class='msg-tooltip'>* CODE-OF-CONDUCT: Add a top notice.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-03-01 13:07:04 -0500'>2022-03-01</span></td><td><a href='/guix/commit/CODE-OF-CONDUCT?id=4254d74b4ca6d4aa78b7fa055fc9ec72a2e93ad3'>CODE-OF-CONDUCT: Update to version 2.1.</a><span class='msg-avail'>...<span class='msg-tooltip'>* CODE-OF-CONDUCT: Update to version 2.1.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2018-05-29 18:29:36 +0200'>2018-05-29</span></td><td><a href='/guix/commit/CODE-OF-CONDUCT?id=a076f19908d06b6df49f1c25c40de8838213cd71'>CODE-OF-CONDUCT: Switch to version 1.4 of the Contributor Covenant.</a><span class='msg-avail'>...<span class='msg-tooltip'>See the discussion at
&lt;https://lists.gnu.org/archive/html/guix-devel/2018-05/msg00146.html&gt;.

* CODE-OF-CONDUCT: Adapt from version 1.4 of the Contributor Covenant.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2016-04-04 23:45:57 +0200'>2016-04-04</span></td><td><a href='/guix/commit/CODE-OF-CONDUCT?id=e314ce1bd7b21229c750ab7132feac8189da87ba'>CoC: Clarify which project we're talking about.</a><span class='msg-avail'>...<span class='msg-tooltip'>* CODE-OF-CONDUCT: Define "project" and "project maintainer" as
suggested by rms.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2015-12-09 14:29:41 +0100'>2015-12-09</span></td><td><a href='/guix/commit/CODE-OF-CONDUCT?id=e15fcdd149cec662fcaf4b550ee32879bd53a591'>Add "Contributor Covenant".</a><span class='msg-avail'>...<span class='msg-tooltip'>* CODE-OF-CONDUCT: New file, adapted from
  &lt;http://contributor-covenant.org/version/1/3/0/code_of_conduct.txt&gt;.
* doc/contributing.texi (Contributing): Mention it.
* Makefile.am (EXTRA_DIST): Add it.
</span></span></td><td>Ludovic Courtès</td></tr>