Add AllowRegexpMatch option to Performance/RedundantEqualityComparisonBlock

[koic]

Follow up #340.

This PR adds AllowRegexpMatch option to Performance/RedundantEqualityComparisonBlock.

# `AllowRegexpMatch: true` (default)

# good
items.all? { |item| item =~ pattern }
items.all? { |item| item.match?(pattern) }

# `AllowRegexpMatch: false`

# bad
items.all? { |item| item =~ pattern }
items.all? { |item| item.match?(pattern) }

AllowRegexpMatch: false by default because regexp.match?('string') often used in block changes to the opposite result:

[/pattern/].all? { |regexp| regexp.match?('pattern') } # => true
[/pattern/].all? { |regexp| regexp =~ 'pattern' }      # => true
[/pattern/].all?('pattern')                            # => false

cc @fatkodima

---

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[fatkodima]

You probably forgot to add Changed: <<next>> to the default.yml.
Lgtm 👍 , thanks.

[koic]

VersionChanged: <<next>> is not written intentionally. Because #340 has not been released yet and the new AllowRegexpMatch option defaults to false so there is backward compatibility.