Is JavaScript async/await Syntactic Sugar for Promises?

Q. Is JavaScript's async/await syntactic sugar for Promise?

A. It is not syntactic sugar.

Q. Why?

A. When you call the Function.prototype.toString method on a function object created with the async function syntax, you get a string starting with async function. This is impossible with Promise alone and cannot be achieved without using the async function syntax.

async function foo() {}
// "async function foo() {}"
console.log(Function.prototype.toString.call(foo)); 

*Note: Here, syntactic sugar is defined as "a syntax that allows a program using it to be consistently rewritten into an equivalent program that does not use that syntax."

Q. So what?

A. Well...