List of features we implement in our parser.
ES6
-[X] Let (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/let)
-[X] Const (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const)
-[X] Arrow Functions (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions)
-[X] Classes (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes)
-[X] Destructuring (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment)
-[X] Promises (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise)
-[X] Modules (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules)
-[X] Generators (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Iterators_and_generators)
-[X] Default Parameters (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Default_parameters)
-[X] Spread Parameters (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax)
-[X] Rest Parameters (https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Functions/rest_parameters)
ES8
-[X] async (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function)
-[X] await (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/await)