conditional typing of resolve() in promise constructor

[tvald]

Fixes #11094, #3356. Replaces the approach in #19633 with a conditional typing of resolve():

resolve: T extends void
  ? (value?: PromiseLike<void>) => void
  : (value: T | PromiseLike<T>) => void

Much thanks to @ahejlsberg and @mhegazy for resolving #21756 and #21823 to make this possible!

[mhegazy]

@rbuckton can you take a look

[falsandtru]

@tvald When T is a union type, resolve function won't be callable. You have to do just as follows.

    new <T extends void>(executor: (resolve: (value?: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void): Promise<T>;
    new <T>(executor: (resolve: (value: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void): Promise<T>;

[falsandtru]

My previous code is not extensible for classes in the current compiler. Fixed as follows.

    new <T>(executor: (resolve: [T] extends [void] ? (value?: T | PromiseLike<T>) => void : (value: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void): Promise<T>;

[mhegazy]

Should be addressed by #22772