merge revision(s) 55429: [Backport #12492]
* class.c (Init_class_hierarchy): prevent rb_cObject which is the class tree root, from GC. [ruby-dev:49666] [Bug #12492]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@59215 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 55429: [Backport #12492]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@59215 b2dd03c8-39d4-4d8f-98ff-823fe69b080e