[Salsa] Support jsdoc `@namespace`

[mhegazy]

Support treating variable declarations with @namespace JSDoc tag as TS namespaces.

/** @namespace */
var Documents = {
    /**
     * An ordinary newspaper.
     */
    Newspaper: 1,
    /**
     * My diary.
     * @private
     */
    Diary: 2
};

[OliverJAsh]

Is there any workaround for this? I want to use my object at the type level. I tried using typeof but it seems that doesn't work with JSDoc:

{
    class Foo {}
    const X = { Foo }

    // line below errors with "Cannot find name 'typeof'"
    /** @type {typeof X.Foo} */
    const foo = new X.Foo()
}

[mhegazy]

would be subsumed by a fix for #16489

[que-etc]

@mhegazy
After this one gets merged, would it be possible to use the import() statement to import all types of a module?

// @filename: interfaces.d.ts
export interface Foo {}

// @filename: usage.js

/** @namespace {import('./interfaces')} NS */

/** @type {NS.Foo} */
let foo;

Seems that @typedef can't be used for it, which is no surprise, of course.

[mhegazy]

you can just use:

// @filename: usage.js

/** @typedef {import('./interfaces').Foo} Foo */

/** @type {Foo} */
let foo;