Error for merging multiple enums without initial initializers

[JsonFreeman]

enum E {
A
}

enum E {
B // Should get an error here for starting a second enum with no initializer
}

Also, you should only look at the second commit (5c3ede7) as the first commit is from a different review (#23)

[CyrusNajmabadi]

I feel like there are two major changes going on here. The first is related to exports, and hte second it the enum change. The enum change looks fine to me. The export change i'm not so clear on.

[JsonFreeman]

Yeah this pull request is for the enum change. I had another pull request (PR) #23 for the other part, but couldn't figure out how to exclude it from this PR. So I consider you signed off on this PR.