Fix setting AtomicReferenceImplementation on TruffleRuby

[eregon]

• This accidentally worked before because until Ruby 2.7 alias_method returns the receiver.
• In Ruby 3 however, alias_method returns the first argument.

$ ruby -ve 'p class C; alias_method :id, :object_id; end'
ruby 2.7.4p191 (2021-07-07 revision a21a3b7d23) [x86_64-linux]
C
$ chruby 3.0.2                                           
$ ruby -ve 'p class C; alias_method :id, :object_id; end'
ruby 3.0.2p107 (2021-07-07 revision 0db68f0233) [x86_64-linux]
:id

This is blocking to implement the change about alias_method;s return value in oracle/truffleruby#2499.
Could you make a bug fix release with this fix soon if possible?

cc @pitr-ch

[eregon]

For the anecdote, I noticed this originated from 877dc76, which worked accidentally because include returns the receiver (still does in Ruby 3).

[eregon]

@pitr-ch or other concurrent-ruby maintainers, could you merge this?

[jdantonio]

@eregon I've given you write permissions. <3

[eregon]

Thank you!

It would be great to have a release including this when maintainers have some time.
For now I made a patch in TruffleRuby (oracle/truffleruby@5ea0bc2), but it is quite messy, so a release of concurrent-ruby would be much better and the patch would not be needed/have no effect when using latest concurrent-ruby.

[jdantonio]

I've been out of the loop for a long time (I only lurk) so I'm hesitant to do a release myself. I'd be fine giving you and @chrisseaton access to RubyGems so that you can both make releases, but I think I'd be overstepping my bounds a bit right now. Hopefully @pitr-ch can jump in soon and give hi sthoughts.