* Fix gem pristine not accounting for user installed gems. Pull request
#2914 by Luis Sagastume.
* Refactor keyword argument test for Ruby 2.7. Pull request #2947 by
SHIBATA Hiroshi.
* Fix errors at frozen Gem::Version. Pull request #2949 by Nobuyoshi
Nakada.
* Remove taint usage on Ruby 2.7+. Pull request #2951 by Jeremy Evans.
* Check Manifest.txt is up to date. Pull request #2953 by David Rodríguez.
* Clarify symlink conditionals in tests. Pull request #2962 by David
Rodríguez.
* Update command line parsing to work under ps. Pull request #2966 by
David Rodríguez.
* Properly test `Gem::Specifications.stub_for`. Pull request #2970 by
David Rodríguez.
* Fix Gem::LOADED_SPECS_MUTEX handling for recursive locking. Pull request
#2985 by MSP-Greg.
Hiroshi SHIBATA