Add spec for identity of String literals in a compare_by_identity Hash
Add spec for identity of String literals in a compare_by_identity Hash

* See https://bugs.ruby-lang.org/issues/12855

eregon/rubyspec,ruby/spec,sgarciac/spec,nobu/rubyspec,eregon/rubyspec,ruby/rubyspec,ruby/rubyspec,sgarciac/spec,nobu/rubyspec,eregon/rubyspec,ruby/spec,ruby/spec,sgarciac/spec,nobu/rubyspec