test: warn when inspector process crashes

If the subprocess being inspected hard crashes, there will be no
information on the log, and the parent process will just wait until
timeout. Logging the error signal when it happens can help developers
understand failures faster.

Signed-off-by: Matheus Marchini <mmarchini@netflix.com>

PR-URL: #32133
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/common/inspector-helper.js

@@ -344,6 +344,9 @@ class NodeInstance extends EventEmitter {
 
     this._shutdownPromise = new Promise((resolve) => {
       this._process.once('exit', (exitCode, signal) => {
+        if (signal) {
+          console.error(`[err] child process crashed, signal ${signal}`);
+        }
         resolve({ exitCode, signal });
         this._running = false;
       });