cluster: use rest param & Reflect.apply

[mithunsasidharan]

Used Reflect.apply for performance gain citing similar change in fs.js

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

cluster

[mithunsasidharan]

@apapirovski : Your thoughts on whether this helps ? This is citing previous PR #17486 . If you feel this helps, I'll open it for review.

[apapirovski]

I would recommend checking whether the cb in this case is user-provided or just something internal within Node.js. Mostly we're switching to Reflect.apply because it's safer when dealing with user-provided callbacks, rather than because it boosts perf by like 1-2% in some edge cases.

[mithunsasidharan]

@apapirovski : It seems to me that it is internal. But does it matter really with regards to perf gain ? In all cases shouldn't it help with that 1-2 % as mentioned ? Thanks.

[apapirovski]

@mithunsasidharan You have to consider whether this is a hot path code or not. Otherwise the 1% faster apply call might convert to 0.00001% real world impact or less. I would say it's probably not worth it.

[mithunsasidharan]

@apapirovski : Sure.. let's park it for now... I'll probably check in detail over weekend and see if it really helps as you mentioned. I'll get back to some coverage for now ! Meanwhile I found this went unnoticed and thought I could raise a PR for it ? nodejs/code-and-learn#72 (comment) Do you suggest we should probably create an issue for this and leave it for some starters ?