[test] Assert that Enums can be represented internally by arbitrary values including Object-reference values.
[test] Assert that Enums can be represented internally by arbitrary values including Object-reference values.

This illustrates part of the solution to #435

baer/graphql-js,gabelevi/graphql-js,graphql/graphql-js,enaqx/graphql-js,tgriesser/graphql-js,enaqx/graphql-js,graphql/graphql-js,tgriesser/graphql-js,jjergus/graphql-js,jjergus/graphql-js,gabelevi/graphql-js,enaqx/graphql-js,graphql/graphql-js,baer/graphql-js