Merge rubygems/bundler HEAD.
Pick from https://github.com/rubygems/rubygems/commit/dfbb5a38114640e0d8d616861607f3de73ee0199
Merge rubygems/bundler HEAD.
Pick from https://github.com/rubygems/rubygems/commit/dfbb5a38114640e0d8d616861607f3de73ee0199