0d9f3bd introduced a noticeable performance regression with various timers benchmarks. For example:

• timers/immediate.js type="clear" performance dropped 77%
• timers/timers-cancel-pooled.js performance dropped 55%
• timers/timers-timeout-pooled.js performance dropped 41%

and many other timers benchmarks/benchmark configs saw double digit drops.

While having a public "get active requests"/"get active handles" API would be nice, I don't think it is worth this kind of penalty if we can't find some way to remedy the performance regressions.

/cc @RaisinTen