Split code generation out of the parser.

[ballercat]

Goal

Unblock #49

Overview

There are a few parts of the parser which envoke the generator directly. This is OK, but it's making it difficult to implement a few things. There aren't a ton of areas of code where this happens, but they should all be cleaned up. In the very early days, the generator was baked into the parser and everything(parsing + generation) happened in one pass, it still kind of does. We should fix it.

Here is a search which should point out all the problem areas

https://github.com/search?utf8=%E2%9C%93&q=generate++user%3Aballercat+repo%3Aballercat%2Fwalt+path%3Asrc%2Fparser+language%3AJavaScript&type=Code&ref=advsearch&l=JavaScript&l=

Problem areas

This change should be rather easy to make, but there might be a few issues.

• Function types are generated and referenced in this manner. Not generating function types on the fly will likely break a few things. Something to watch out for.

Acceptance Criteria

• Move all generator calls out of the parser
• Have parser spit out the AST ONLY
• Have generator walk the AST and spit out IR
• Make sure tests pass