merge revision(s) 54970: [Backport #12367]
* insns.def (defineclass): Also raise an error when redeclaring the superclass of a class as Object and it has another superclass. [Bug #12367] [ruby-core:75446] * test/ruby/test_class.rb: test for above.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@55402 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 54970: [Backport #12367]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@55402 b2dd03c8-39d4-4d8f-98ff-823fe69b080e