r?
After this patch, macros declared in a module, function, or block can only be used inside of that module, function or block, with the exception of modules declared with the #[macro_escape] attribute; these modules allow macros to escape, and can be used as a limited macro export mechanism.
This pull request also includes miscellaneous comments, lots of new test cases, a few renamings, and a few as-yet-unused data definitions for hygiene.
Macro scope is now delimited by function, block, and module boundaries,
except for modules that are marked with #[macro_escape], which allows
macros to escape.
These commits take the old bitv implementation and modernize it with an explicit self, some minor touchups, and using what I think is some more recent patterns (like `::new` instead of `Type()`).
Additionally, this adds an implementation of `container::Set` on top of a bit vector to have as a set of `uint`s. I initially tried to parameterize the type for the set to be `T: NumCast` but I was hitting build problems in stage0 which I think means that it's not in a snapshot yet, so it's just hardcoded as a set of `uint`s now. In the future perhaps it could be parameterized. I'm not sure if it would really add anything, though, so maybe it's nicer to be hardcoded anyway.
I also added some extra methods to do normal bit vector operations on the set in-place, but these aren't a part of the `Set` trait right now. I haven't benchmarked any of these operations just yet, but I imagine that there's quite a lot of room for optimization here and there.
r?
Apply deriving_eq to the data structures in ast.rs, and get rid of the custom definitions of eq that were everywhere. resulting ast.rs is about 400 lines shorter.
Also: add a few test cases and a bunch of comments.
Also: change ast_ty_to_ty_cache to use node ids rather than ast::ty's. I believe this was a suggestion related to my changes, and it appears to pass all tests.
Also: tiny doc fix, remove references to crate keywords.
