Repro for crbug.com/1270780

This checks that the debugger breaks correctly on promise rejections in async generators

Steps

  1. Open DevTools
  2. Turn on Pause on exceptions in the Sources panel (while leaving Pause on uncaught exceptions turned off)
  3. Click
  4. Observe that the debugger doesn't stop
  5. Turn on Pause on uncaught exceptions
  6. Click
  7. Observe that the debugger stops in crbug-1270780.js:6
  8. Hit Resume
  9. Observe that the script finishes execution