semantic: Remove goto usage.
semantic: Const can safely convert to immutable.
ir: Unary.type is optional.
semantic: First pass at unification of overload/extyper type verification.
semantic: Don't test null types.
semantic: Move all variable declarations to the top of the function.
semantic: Assign the vtable in a constructor prelude.
volt: Fix a few typos in comments.
volt: Override Work.opEquals for DMD 2.066.
token: Remove filter dependency from lexer.
token: Treat doc comments as tokens.
parser: Attach comments to IR nodes.
visitor: Add JSON and HTML output for doccomments.