Add a command to peek at otherwise inaccessible context

Sometimes we run into inaccessible context when debugging, such as anonymous arguments: *, **, &, ..., or arguments that conflict with Ruby keywords, such as class, end, if.

In these situations, it would be useful to be able to peek at the context. Maybe there’s a better name for this concept, but essentially it would be an IRB command that just returns *args, **kwargs, and &block.

def peek(*args, **kwargs, &block)
  { args:, kwargs:, block: }
end

This would support things like:

peek(*)
peek(**)
peek(&)
peek(...)
peek(class:, end:, if:)

Does this sound useful to anyone else?

Start by locating how IRB commands are defined and how method arguments are evaluated in the interactive Ruby session. Compare the proposed peek behavior for *, **, &, ..., and keyword-conflicting names, then determine a command name and interface. Done means the command can expose these otherwise inaccessible values with documented behavior and tests for the examples in the issue.