merge revision(s) 56980,56981: [Backport #13004]
extension.rdoc: fix rb_get_kwargs [ci skip] * doc/extension.rdoc: [DOC] optional keyword arguments are
defaulted to Qundef. ignored keys are kept in the hash but a new Hash is not created. [ruby-dev:49893] [Bug #13004]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@57215 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 56980,56981: [Backport #13004]
defaulted to Qundef. ignored keys are kept in the hash but a
new Hash is not created. [ruby-dev:49893] [Bug #13004]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@57215 b2dd03c8-39d4-4d8f-98ff-823fe69b080e