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async_hooks: fast-path for PromiseHooks in JS

Rodrigo Muino Tomonari requested to merge github/fork/Qard/promise-hooks-in-js into master

This is an attempt to eliminate the GC-tracking of promises needed to emit destroy events to async_hooks if there is nothing listening to those events. I've replicated the PromiseHook handler and PromiseWrap behaviour in JS to allow a fast-path for handling promise-related events when there is no destroy hook present and therefore no need for expensive gc-tracking. This should significantly improve the performance of async_hooks in promise-heavy applications for the typical/suggested case of context management with AsyncLocalStorage.

With this comes a few important changes to consider:

  • Promises will no longer emit trace events unless there is a destroy hook
  • The resource for a promise event will no longer have the isChainedPromise property (Though there are ideas of how this could be restored, if there are objections)

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