benchmark: adjust configuration for string-decoder bench

According to #59186 this benchmark file takes 6 hours to complete a full benchmark/compare.js script (60 runs in total) and this regression tests unrealitics to do between Node.js releases. By using calibrate-n scripts I could find a better N also ajusting some bench configs. e.g: avoid dead code elimination by V8. PR-URL: #59187 Refs: #59186 Reviewed-By: Vinícius Lourenço Claro Cardoso <[email protected]> Reviewed-By: Luigi Pinca <[email protected]>

Author: RafaelGSS

benchmark/string_decoder/string-decoder.js

@@ -1,11 +1,12 @@
 'use strict';
 constcommon=require('../common.js');
 constStringDecoder=require('string_decoder').StringDecoder;
+constassert=require('node:assert');
 
 constbench=common.createBenchmark(main,{
 encoding: ['ascii','utf8','base64-utf8','base64-ascii','utf16le'],
-inLen: [32,128,1024,4096],
-chunkLen: [16,64,256,1024],
+inLen: [32,128,1024],
+chunkLen: [16,256,1024],
 n: [25e5],
 });
 
@@ -75,10 +76,13 @@ function main({encoding, inLen, chunkLen, n }){
 
 constnChunks=chunks.length;
 
+letavoidDeadCode;
 bench.start();
 for(leti=0;i<n;++i){
+avoidDeadCode='';
 for(letj=0;j<nChunks;++j)
-sd.write(chunks[j]);
+avoidDeadCode+=sd.write(chunks[j]);
 }
 bench.end(n);
+assert.ok(avoidDeadCode);
 }