marshal.c: check instance variable count
* marshal.c (w_obj_each): ensure that no instance variable was
added while dumping other instance variables. [Bug #15968]
Hoisted out w_ivar_each
marshal.c: check instance variable count
* marshal.c (w_ivar_each): ensure that no instance variable was
removed while dumping other instance variables. [Bug #15968]
merge revision(s) c9423b016cfeab852bc5a829e55e0a11f80b3ab7,0b1e26398e018116180bf41cb63887f77d5d1b82,78ee2c245331e353e218b8fac9ca722a2bcd8fea: [Backport #15968]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@67861 b2dd03c8-39d4-4d8f-98ff-823fe69b080e