[Ruby 3.0 support] Add support for Array subclass methods to return Array

[Strech]

This PR will add adjust Array that its subclasses on below methods return Array (from the Ruby 3.0 support #2453)

• Array#drop
• Array#drop_while
• Array#flatten
• Array#slice!
• Array#slice / Array#[]
• Array#take
• Array#take_while
• Array#uniq
• Array#*

I find out that for Array.slice I would need to adjust Java code. I will dig a bit to get the context around, but I probably would need some help (or an example)

[eregon]

I will dig a bit to get the context around, but I probably would need some help (or an example)

You're welcome to ask any question on Slack :)

[eregon]

Sorry about the incorrect classification as [easy, pure ruby], it sounds like this change needs more Java changes than I anticipated. However, I think these Java changes should be relatively easy.

[Strech]

@eregon Thanks for the review and tips, definitely helps! I've resolved all the notes, but I have some doubts about one where I should return the comment in place 🤔

[Strech]

👋🏼 Hola @eregon may I ask for one more review? I've applied all the tips you gave me and seems all check passed (but before I squash everything and pushed)

[eregon]

Could you rebase to latest master? When you do, just drop the changes to spec/truffleruby.mspec as on master RUBY_VERSION is already 3.0.2 and so there is no need to change :next.

[eregon]

Ah and instead of :next you'll want to run jt untag spec/ruby/core/array to remove tags for now-passing specs.

[Strech]

Thank you one more time @eregon. All fixes were applied

[eregon]

Looks great, thank you!