Make .ver and .auth MetaModel methods available on Packages

[zoffixznet]

Fixes RT#128579

Tests: Raku/roast#134

This adds .^ver and .^auth methods to packages, fixing this:

$ perl6 -e 'my class Z:ver<1.2.3>:auth<me> {}; say [ Z.^ver(), Z.^auth ];'
[v1.2.3 me]
$ perl6 -e 'my module Z:ver<1.2.3>:auth<me> {}; say [ Z.^ver(), Z.^auth ];'
[v1.2.3 me]
$ perl6 -e 'my package Z:ver<1.2.3>:auth<me> {}; say [ Z.^ver(), Z.^auth ];'
Method 'ver' not found for invocant of class 'Perl6::Metamodel::PackageHOW'
  in block <unit> at -e line 1

$ 

Relevant IRC Conversation: http://irclog.perlgeek.de/perl6/2016-07-08#i_12808945

[jnthn]

Um, this wasn't an oversight, it was intentional. Not supporting auth/ver is one of the things that distinguishes a package from a module. Packages play the role of being replaceable stubs. For example:

jnthn@lviv:~/dev/rakudo$ ./perl6-m -e 'package A { }; package A { }'
jnthn@lviv:~/dev/rakudo$ ./perl6-m -e 'package A { }; module A { }'
jnthn@lviv:~/dev/rakudo$ ./perl6-m -e 'module A { }; module A { }'
===SORRY!=== Error while compiling -e
Redeclaration of symbol A
at -e:1
------> module A { }; module A⏏ { }

Notice how the first two are fine, only the last one is an error. Attaching identify to something that we've defined as freely replaceable feels odd. So, I'm inclined to revert this.

[lizmat]

FWIW, I'm inclined to agree.