While it isn't technically needed because regenerator already handles
async functions, it doesn't play well with the Promise detection logic
used by @babel/preset-env's useBuiltIns and @babel/transform-runtime.
The plugin exclusion logic isn't removed, because
1) it will be useful when merging @babel/preset-modules
into @babel/preset-env
2) if/when regenerator will support injecting a custom promise,
we can enable this optimization again
* destructuring private fields with array pattern / object pattern
* wip: new test cases
* destrucuring and rest for private properties
* test case for loose private-loose
* add transform-desturcturing for exec
* update test case
* remove getPrototypeOf imports from get and set
* wip: destructure super assignment
* throw "Destructuring to a super field is not supported yet."
* fix tests and fix assignment pattern
* remove CallExpression from AssignmentPattern
* Introduce scope tracking
* Fix tests
* Add new tests
* Remove constructor-super check from transform as it is now in parser
* Correctly handle class properties and class scope
* Fix duplicate name check
* Convert scope identifier storage to array
* Enter a new scope in typescript module blocks
* Add test for duplicate declaration
* Rename error for duplicate exports
* Treat class declarations as lexical declaration
* Update whitelist
* Add tests
* Fix scope tracking for function declarations
* Migrate try-catch duplicate error
* Fix test
* More tests
* One more test
* Make scope a separate class and fix review comments
* Do not allow new.target in top scope arrow function
* Correctly enter new scope for declare module and treat type aliases as lexical declarations
* Tests for typescript scope tracking to not mark type aliases as duplicate
* Fix flow scope tracking
* Remove ident from test names as redundant
* Add test case for var and function
* Improve error messages
* Improve literal regex
