events: use spread function param in emit

With recent changes in V8, it is now as performant or faster to use
spread parameter within EventEmitter.prototype.emit, especially
in cases where looping over arguments is required.

events/ee-emit.js n=2000000               4.40 %    *** 1.505543e-06
events/ee-emit-1-arg.js n=2000000         2.16 %    *** 2.434584e-10
events/ee-emit-2-args.js n=2000000        1.05 %     ** 0.001764852
events/ee-emit-3-args.js n=2000000        2.18 %    *** 3.234954e-08
events/ee-emit-6-args.js n=2000000       17.17 %    *** 1.298702e-103
events/ee-emit-10-args.js n=2000000      17.14 %    *** 1.144958e-97

This has a knock-on effect for modules that use events extensively,
such as http2:

http2/headers.js nheaders=0 n=1000        2.10 %    *** 6.792106e-11

PR-URL: https://github.com/nodejs/node/pull/16212


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>