Async-context formalization and diagnostics support #107

Updating text here to better reflect reality - mike-kaufman

Current Status:

• high-level description of async context is checked into Diag repo in form of slides
• Update slides to account for the following
  • explicit APIs for how to do property lookups. Support "lazy init promises"

    var p;
    app.get('/', (req, res) = {
       if (!p) { 
           p = someAsyncFuncThatReturnsAPromise(); 
       }
       p.then(() => {…});
    });

  • Promise.all(), Promise.race()
  • Async/Await examples
  • generator examples
  • async generator examples
  • async recurision and path compression support (e.g., f = () = > { setTimeout(f, 1000); })
  • specific API changes (I.e., what APIs/properties get exposed through JS to users)
• Get plan on how to take to TC-39
• Identify how ready-context can be implemented based on current promise hooks APIs
• Understand perf impact