revert deprecation of scope class

[WalterBright]

See #13767

This is another one where the scope class doesn't actually hurt anything.

I suggest with things like this that do not actually hurt anything that we just accept them and keep them doing what they do without complaint. We can perhaps add a switch -obsolete which will tell the user about use of such obsolete features.

See also: #15379 and deprecating class alias this.

[dlang-bot]

Thanks for your pull request, @WalterBright!

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Testing this PR locally

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dub run digger -- build "master + dmd#15380"

[WalterBright]

Or maybe a -wo switch, which will emit warnings about obsolete features.

[rikkimax]

These features should still be removed at some point. I would like to one day use body for instance.

However, a separate warning that dub turns on by default? Sure, I like that idea.

[WalterBright]

You can already use body as an identifier, this doesn't turn it off.

[adamdruppe]

good.

[tgehr]

Nice! TBH I don't really see why this should even be considered obsolete. It's nice to be able to declare a class whose destructor has to be called reliably, the check is very cheap, and the syntax is intuitive.