cluster: work with v8_inspector

PR-URL: #6792
Reviewed-By: jasnell - James M Snell <jasnell@gmail.com>
Reviewed-By: addaleax - Anna Henningsen <anna@addaleax.net>
Reviewed-By: bnoordhuis - Ben Noordhuis <info@bnoordhuis.nl>

Author: cjihrig

lib/cluster.js

@@ -304,7 +304,9 @@ function masterInit() {
     workerEnv.NODE_UNIQUE_ID = '' + id;
 
     for (var i = 0; i < execArgv.length; i++) {
-      var match = execArgv[i].match(/^(--debug|--debug-(brk|port))(=\d+)?$/);
+      var match = execArgv[i].match(
+        /^(--inspect|--debug|--debug-(brk|port))(=\d+)?$/
+      );
 
       if (match) {
         const debugPort = process.debugPort + debugPortOffset;