- Generate tagged unions in C backend for enums with data
- Add HirEnumVariant type with fields and namedFields
- Support _Tag and _Data field access in sema
- Support enum variant constants (Result_Ok, Result_Err)
- Support _Data union field access (Ok_0, Err_0, etc.)
- Add algebraic_enums.bux example
Example:
enum Result {
Ok(int),
Err(String)
}
let r: Result = Result { tag: Result_Ok };
r.data.Ok_0 = 42;