Missing label "naked bracket"

[schneems]

If a developer wanted to return an empty hash or array but forgot one side of the bracket, we don't always label it.

This has a label:

$ exe/dead_end /tmp/scratch.rb

DeadEnd: Unmatched `]` detected

file: /tmp/scratch.rb
simplified:

      1  def foo
    ❯ 2    [
      3  end

But not:

$ exe/dead_end /tmp/scratch.rb

file: /tmp/scratch.rb
simplified:

      1  def foo
    ❯ 2    ]
      3  end

The syntax error is this one, which we're not catching for annotation:

$ ruby -wc /tmp/scratch.rb
/tmp/scratch.rb:2: syntax error, unexpected ']'