e65402364d
The Binder and related types have been refactored to use the new `NodeKind` enum instead of the previous `BoundKind`. This commit updates all references to use the new structure, ensuring consistency across the compiler's AST representation. Key changes include: - Replacing `BoundKind` with `NodeKind` in the Binder's `bind` and `visit` methods. - Updating pattern matching and field access to reflect the new enum variants (e.g., `NodeKind::Def` instead of `BoundKind::Define`). - Adjusting identifier bindings to use the new `IdentifierBinding` enum. - Reflecting changes in `DefBinding`, `AssignBinding`, and `LambdaBinding` structures. - Ensuring all newly created nodes use `NodeKind` and the appropriate metadata.