test_assignment.rb: split test_assign
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46363 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_assignment.rb: split test_assign
forms.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46363 b2dd03c8-39d4-4d8f-98ff-823fe69b080e