plugin bug/misbehavior can lead to silent exit (also see #606 )

[pkit]

• Rollup Version: any
• Operating System (or Browser): Linux
• Node Version (if applicable):
• Link to reproduction (IMPORTANT, read below): https://repl.it/@pkit/async-no-resolve

Expected Behavior

Timeout

Actual Behavior

Silent exit, see #606

Need to add a race with timeout and some sort of a listener queue.
Otherwise it will just exit on any buggy plugin code. And people cannot be expected to be able to debug each and every plugin for potential misbehavior.

[pkit]

Used async_hooks to track pending promises and, boy, tens of pending promises on rollup exit.
Probably a lot of plugins have bugs related to that.