Rubocop: Prefer `block_given?` to `iterator?`

[znz]

Is your feature request related to a problem? Please describe.

The iterator? form is mildly deprecated.

Describe the solution you'd like

Recommend to use block_given? instead of iterator?.

Additional context

• Prefer block_given? to iterator?
• Feature #15547 deprecate iterator?

[Drenmi]

Oh, wow. That is some old stuff. Had never heard about this alias before. 🙂

[tejasbubane]

I assume this would go in a new Lint/BlockGiven cop. Or is there a better place in existing cops? @Drenmi

[koic]

I think we can create the new Lint/KernelIteratorPredicate cop, which will be the deprecated method name.