benchmark: update iterations in benchmark/util/splice-one.js

[Septa2112]

Refs: #50571

In case util/splice-one.js, when only pos=end I found that the performance gap between node-21.x and node-20.x increased from -15% to 5% after I changed iterations from default 1e5 to 5e6. (node-20.x is the baseline.)

To make sure there was no problem with this modification, I tested the other 8 situations in this case (there are 9 situations in total, 3 types of pos, 3 types of size).

Here is the tests data and the new binary is node 21.x.

node-21.x vs node-20.x

• pos=end

util/splice-one.js size=10 pos='end' n=100000        ***    -15.03 %       ±0.82% ±1.09% ±1.42%
util/splice-one.js size=10 pos='end' n=1000000        ***     -1.63 %       ±0.36% ±0.49% ±0.63%
util/splice-one.js size=10 pos='end' n=5000000        ***      5.07 %       ±0.52% ±0.70% ±0.93%

util/splice-one.js size=100 pos='end' n=100000        ***    -14.96 %       ±0.91% ±1.21% ±1.58%
util/splice-one.js size=100 pos='end' n=1000000        ***     -1.85 %       ±0.38% ±0.51% ±0.67%
util/splice-one.js size=100 pos='end' n=5000000        ***      4.59 %       ±0.20% ±0.26% ±0.35%

util/splice-one.js size=500 pos='end' n=100000        ***    -16.60 %       ±0.84% ±1.12% ±1.47%
util/splice-one.js size=500 pos='end' n=1000000        ***     -1.60 %       ±0.45% ±0.60% ±0.79%
util/splice-one.js size=500 pos='end' n=5000000        ***      4.61 %       ±0.20% ±0.26% ±0.35%

• pos=middle

util/splice-one.js size=10 pos='middle' n=100000        ***     -4.40 %       ±0.84% ±1.12% ±1.46%
util/splice-one.js size=10 pos='middle' n=1000000                -0.70 %       ±2.08% ±2.79% ±3.69%
util/splice-one.js size=10 pos='middle' n=5000000        ***      2.64 %       ±0.37% ±0.50% ±0.65%

util/splice-one.js size=100 pos='middle' n=100000        ***     -1.69 %       ±0.43% ±0.58% ±0.75%
util/splice-one.js size=100 pos='middle' n=1000000         **      1.49 %       ±1.00% ±1.35% ±1.79%
util/splice-one.js size=100 pos='middle' n=5000000         **      1.60 %       ±1.05% ±1.42% ±1.88%

util/splice-one.js size=500 pos='middle' n=100000        ***     -0.79 %       ±0.28% ±0.37% ±0.49%
util/splice-one.js size=500 pos='middle' n=1000000        ***     -0.17 %       ±0.06% ±0.08% ±0.10%
util/splice-one.js size=500 pos='middle' n=5000000        ***     -0.11 %       ±0.04% ±0.06% ±0.07%

• pos=start

util/splice-one.js size=10 pos='start' n=100000        ***     -4.13 %       ±0.57% ±0.75% ±0.98%
util/splice-one.js size=10 pos='start' n=1000000          *     -1.17 %       ±0.89% ±1.20% ±1.59%
util/splice-one.js size=10 pos='start' n=5000000        ***      0.36 %       ±0.16% ±0.22% ±0.28%

util/splice-one.js size=100 pos='start' n=100000        ***     -0.65 %       ±0.31% ±0.41% ±0.54%
util/splice-one.js size=100 pos='start' n=1000000         **      0.83 %       ±0.49% ±0.65% ±0.87%
util/splice-one.js size=100 pos='start' n=5000000        ***      1.16 %       ±0.52% ±0.69% ±0.92%

util/splice-one.js size=500 pos='start' n=100000          *     -0.14 %       ±0.12% ±0.15% ±0.20%
util/splice-one.js size=500 pos='start' n=1000000                -0.02 %       ±0.07% ±0.09% ±0.12%
util/splice-one.js size=500 pos='start' n=5000000                 0.02 %       ±0.11% ±0.14% ±0.19%

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55701/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/55816/

[nodejs-github-bot]

Landed in f8c27e6