Mostly requires adding ** in either calls or method definitions.

This was never the right place. The method got there just by evolution,
not by design. Move it within default methods, where it suits better.

Since this method is presumably used just internally, it should be safe
to deprecate it and remove later.

https://github.com/rubygems/rubygems/commit/0c0dd9458a

  I picked the commit from 3c469e0da538428a0ddd94f99aa73c32da22e8ba

Closes: https://github.com/ruby/ruby/pull/2154

  The current master branch is
  https://github.com/rubygems/rubygems/commit/97b264f0fa248c864b6ee9a23d3ff1cdd217dddb

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67415 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  This version contains the some style changes by RuboCop.

    * https://github.com/rubygems/rubygems/commit/9d810be0ede925fb2e3af535848582c3f8e0e72f
    * https://github.com/rubygems/rubygems/commit/61ea98a727fb1b76b6fac52d74107ee4b02aaef2
    * https://github.com/rubygems/rubygems/commit/795893dce3c5f8540804fc08144cc6a90f086b13
    * https://github.com/rubygems/rubygems/commit/9be7858f7f17eae3058204f3c03e4b798ba18b9c

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67074 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  It fixed the issues of RubyGems 3.0.0.
  https://blog.rubygems.org/2018/12/23/3.0.1-released.html

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66499 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

  * Enable Style/MethodDefParentheses in Rubocop
    https://github.com/rubygems/rubygems/pull/2478
  * Enable Style/MultilineIfThen in Rubocop
    https://github.com/rubygems/rubygems/pull/2479
  * Fix required_ruby_version with prereleases and improve error message
    https://github.com/rubygems/rubygems/pull/2344
  * Fix bundler rubygems binstub not properly looking for bundler
    https://github.com/rubygems/rubygems/pull/2426

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65904 b2dd03c8-39d4-4d8f-98ff-823fe69b080e