hash.c: revert
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44263 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
hash.c: revert
warnings, due to compatibility for HashWithDifferentAccess.
[ruby-core:59154] [Bug #9223]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44263 b2dd03c8-39d4-4d8f-98ff-823fe69b080e