* object.c (Module#const_defined?): [DOC] Revise the documentation.
  Patch by Xavier Noria.
  [Fixes GH-754] https://github.com/ruby/ruby/pull/754

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48320 b2dd03c8-39d4-4d8f-98ff-823fe69b080e