Expose API for getting JSDoc nodes in TypeScript files

Closure adds various semantic JSDoc annotations that aren't currently modeled by TypeScript, such as @export (unrelated to TS export) and @nosideeffects.
https://developers.google.com/closure/compiler/docs/js-for-compiler#overview

As part of our tool chain to run TypeScript through Closure we'd like to be able to munge these via the TypeScript API. It appears TypeScript gathers JSDoc comments when parsing JavaScript -- is there a good reason to not gather these in TypeScript as well?

Specifically, I believe my suggestion amounts to removing the "if" statement in the below code (though I'm not certain this is the right place) in parser.ts:

        function addJSDocComment<T extends Node>(node: T): T {
            if (contextFlags & NodeFlags.JavaScriptFile) {
                ...all of the code is in here...
            }
        }

Comienza en parser.ts, en addJSDocComment, e inspecciona cómo la guarda NodeFlags.JavaScriptFile limita la recopilación de JSDoc. Compara la ruta de análisis existente de JavaScript con el análisis de archivos TypeScript y revisa la discusión del issue para determinar el límite previsto de la API. Se considera terminado cuando se pueda acceder a los nodos JSDoc de los archivos TypeScript mediante la API de TypeScript, incluidas las anotaciones de Closure como @export y @nosideeffects.