* lib/rubygems:  Update to RubyGems master d8f12e2.  This increases the
  speed of `gem install --ignore-dependencies` which helps bundler
  tests.
* test/rubygems:  ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44270 b2dd03c8-39d4-4d8f-98ff-823fe69b080e