[PATCH] Add DarwinInputGraph

[Rui Ueyama]

I'm not still sure whether or not "InputGraph" thing was after all the right way to abstract the input file list. That often makes easy things hard. In this case, sorting a list of input files became that hard. When I proposed the idea I was thinking that would make this kind of things easier to handle. I don't think the current shape of the API is not desirable at least. Or the fundamental idea was not very good.

One thing we probably should consider is, in my opinion, we are pushing too hard to separate all ports. We are trying to write any architecture-dependent code into architecture-specific file. But the natural border of API doesn't always fit to the architecture dependent/independent border. We should probably relax that constraint a bit where that makes sense and write code that's short and easier to understand.

That being said, the InputGraph already exists there, and if I use that I'd do that way. This patch doesn't make things worse, so LGTM.

http://reviews.llvm.org/D5876