proc.c: revert r39224
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39599 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
proc.c: revert r39224
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39599 b2dd03c8-39d4-4d8f-98ff-823fe69b080e