Destructuring with computed property loses type information

[ajafff]

TypeScript Version: 2.9.0-dev.20180407

Search Terms: destructuring computed

Code

let { [Symbol.iterator]: destructured } = []; // destructured is any
let elementAccess = [][Symbol.iterator]; // elementAccess is type () => IterableIterator<never>

declare function get<T>(): T;

let { [get<'prop'>()]: computed } = get<{ prop: string }>(); // computed is any
let { prop } = get<{ prop: string }>(); // prop is string

Expected behavior:
destructured has the same type as elementAccess; computed has the same type as prop.

Actual behavior:
Destructuring with computed property always results in any.

Playground Link: http://www.typescriptlang.org/play/#src=let%20%7B%20%5BSymbol.iterator%5D%3A%20destructured%20%7D%20%3D%20%5B%5D%3B%0Alet%20elementAccess%20%3D%20%5B%5D%5BSymbol.iterator%5D%3B%0A%0Adeclare%20function%20get%3CT%3E()%3A%20T%3B%0A%0Alet%20%7B%20%5Bget%3C'prop'%3E()%5D%3A%20computed%20%7D%20%3D%20get%3C%7B%20prop%3A%20string%20%7D%3E()%3B%0Alet%20%7B%20prop%20%7D%20%3D%20get%3C%7B%20prop%3A%20string%20%7D%3E()%3B

Related Issues:
#17566 but that one is only about index signatures