Upgrade to TypeScript 4.0 (#8982)
* Upgrade to TypeScript 4.0
* Update tests
* Fix changelog
* Revert invalid label tests
* Set loggerFn to false
* Use TS 4.0
* Apply logical assginment test for TypeScript
* Remove hack for NamedTupleMember
* workaround for TypeScript 4.0 in src/language-js/utils.js
Co-authored-by: Christopher J. Brody <chris.brody+brodybits@gmail.com>
