async/await 関連
- Implement parsing and semantic analysis of await operator #33199
- Implement restrictions on calls to 'async' functions. #33399
- Add support for 'async' closures. #33408
- async autoclosures are only legal on async functions. #33446
- Treat 'await' as a contextual keyword. #33457
- Infer @asyncHandler from protocol requirements. #33488
- Fix nested await/try parsing and effects checking. #33807
- Enable support for @objc async methods #33837
- Allow overload 'async' with non-async and disambiguate uses. #33862