fix(lib/es2015): Fix types of Reflect methods

[ExE Boss (ExE-Boss)]

Unlike #35608, this only fixes the types so that the return types of Reflect.ownKeys(…) and Reflect.getPrototypeOf(…) are correct.

Blocks:

• feat(lib/es2015): Add typed overloads to Reflect #35608
• fix(lib/es2015): Fix definition of ProxyHandler #35594

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Fixes#34626

/cc Jessica Franco (@Jessidhia)Orta Therox (@orta)Ron Buckton (@rbuckton)Nathan Shively-Sanders (@sandersn)

[TypeScript Bot (typescript-bot)]

This PR doesn't have any linked issues. Please open an issue that references this PR. From there we can discuss and prioritise.

[Orta Therox (orta)]

I compared each function to the MDN docs for the reflect API, and that all seems to look right to me - thanks ExE Boss (@ExE-Boss)

[Robert Monfera (monfera)]

ExE Boss (@ExE-Boss) great change, thanks! Looks like lib/lib.es2015.reflect.d.ts needs to be updated for userland code who install via eg. yarn and "typescript": "microsoft/TypeScript#master", in the devDependencies; also tried yarn add -D typescript@next, still getting the old definitions from lib/lib.es2015.reflect.d.ts. Maybe there's some extra build step?

[Benjamin Vincent (Luxcium)]

I would like to know what is the return type of Reflect.ownKeys(target) is it of Type '(string | number | symbol)[]' or of Type '(string | symbol)[]' ??? (Sorry to be so confused I am the kind of person who likes to annotate all my functions output types and now I am using /* : (string | number | symbol)[] */ yes with the /* and the */ haha !!!

[ExE Boss (ExE-Boss)]

Benjamin Vincent (@Luxcium) The correct return type of Reflect.ownKeys(target) is (string | symbol)[]:

• https://tc39.es/ecma262/#sec-reflect.ownkeys
• https://tc39.es/ecma262/#sec-invariants-of-the-essential-internal-methods