- Add TestAllExpressionTypes covering all expression nodes
- Add TestAllStatementTypes covering all statement nodes
- Add TestAllTypeExpressions covering all type expressions
- Add TestControlFlowPatterns demonstrating complex control flow
- Fix formatter for field initializers, type spacing, and labels
- Fix handling of orelse blocks, switch payloads, and errdefer
- Remove duplicate test functions from previous edits
- Tests serve as documentation/examples for AST construction