test: pass through stderr in benchmark tests

This helps a lot with debugging failing benchmark tests, which would otherwise just print an assertion for the exit code (something like `+1 -0`, which yields almost no information about a failure). PR-URL: #21860 Reviewed-By: Rich Trott <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Gireesh Punathil <[email protected]> Reviewed-By: Trivikram Kamat <[email protected]> Reviewed-By: Gabriel Schulhof <[email protected]>

Author: addaleax

test/common/benchmark.js

@@ -20,7 +20,10 @@ function runBenchmark(name, args, env){
 
 constmergedEnv=Object.assign({},process.env,env);
 
-constchild=fork(runjs,argv,{env: mergedEnv,stdio: 'pipe'});
+constchild=fork(runjs,argv,{
+env: mergedEnv,
+stdio: ['inherit','pipe','inherit','ipc']
+});
 child.stdout.setEncoding('utf8');
 
 letstdout='';