* hash.c (rb_hash_{le,lt,ge,gt}): new methods, Hash#<=, Hash#<,
Hash#>=, Hash#>, to test if all elements of a hash are also
included in another hash, and vice versa.
[ruby-core:68561] [Feature #10984]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52518 b2dd03c8-39d4-4d8f-98ff-823fe69b080e