Ruby » Ruby master

revert [Bug #9605]

• enum.c: revert r45284, r45286, r45292. it conflicts with
  existing behaviors. [Bug #9605]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45322 b2dd03c8-39d4-4d8f-98ff-823fe69b080e