compilation-perl

This is a spot of code adding `compilation-error-regexp-alist' patterns
for Perl

    * die messages with "during global destruction" suffix
    * Pod::Checker module, including its podchecker program
    * Pod::Simple module
    * Test module
    * Test::Harness module
    * Test::Builder module and its users like Test::More
    * xsubpp program

And toning down Emacs 22 "gnu" pattern for the benefit of

    * Glib::Log module, shared by all of Gtk2-Perl

Emacs already has patterns for perl's normal compile and run errors, but
the above are all a bit different.