This should hopefully improve our compilation times, both from a clean build and from an incremental compilation snapshot.
Next would be the parser, but it imports `Context`, so it'll require a bit more work.
The number of file changes is obviously big, but almost nothing was changed, I just moved everything to another crate and readjusted the imports of the `parser` module. (Though, I did have to change some details, because there were some functions on the ast that returned `ParseError`s, and the tests had to be moved to the parser)
José Julián Espina