events: improve arrayClone performance

[mscdex]

Benchmark results:

 events/ee-emit.js listeners=10 argc=0 n=6000000                            0.73 %       ±3.58% ±4.82% ±6.37%
 events/ee-emit.js listeners=100 argc=0 n=6000000                  ***      8.96 %       ±0.48% ±0.64% ±0.84%
 events/ee-emit.js listeners=2 argc=0 n=6000000                    ***     16.72 %       ±1.07% ±1.43% ±1.87%
 events/ee-emit.js listeners=3 argc=0 n=6000000                    ***     13.46 %       ±0.66% ±0.88% ±1.14%
 events/ee-emit.js listeners=30 argc=0 n=6000000                   ***      6.85 %       ±0.79% ±1.06% ±1.40%
 events/ee-emit.js listeners=4 argc=0 n=6000000                    ***     10.06 %       ±4.48% ±6.04% ±8.02%
 events/ee-emit.js listeners=5 argc=0 n=6000000                    ***     17.93 %       ±3.18% ±4.28% ±5.68%
 events/ee-emit.js listeners=6 argc=0 n=6000000                    ***     13.06 %       ±3.26% ±4.34% ±5.67%
 events/ee-emit.js listeners=7 argc=0 n=6000000                            -2.73 %       ±3.11% ±4.19% ±5.56%
 events/ee-listeners.js raw='true' listeners=10 n=40000000         ***     19.09 %       ±1.78% ±2.39% ±3.16%
 events/ee-listeners.js raw='true' listeners=2 n=40000000          ***     43.05 %       ±1.10% ±1.47% ±1.91%
 events/ee-listeners.js raw='true' listeners=3 n=40000000          ***     47.95 %       ±1.35% ±1.80% ±2.36%
 events/ee-listeners.js raw='true' listeners=4 n=40000000          ***     58.57 %       ±2.62% ±3.52% ±4.64%
 events/ee-listeners.js raw='true' listeners=5 n=40000000          ***     65.12 %       ±1.31% ±1.74% ±2.27%
 events/ee-listeners.js raw='true' listeners=6 n=40000000          ***     74.60 %       ±1.61% ±2.15% ±2.81%
 events/ee-listeners.js raw='true' listeners=7 n=40000000           **      2.31 %       ±1.37% ±1.84% ±2.41%

Note: array.slice() roughly equals the performance of the original for-loop at a certain point but gets slightly faster as the number of elements increases, which explains some of the results above.

Checklist

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

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/31755/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/31783/