test: temporarily back out changes from 11c1bae

Temporarily revert the changes to test/ from commit 11c1bae ("lib: make
--debug-port work with cluster") to ease cherry-picks from joyent/node.

PR-URL: https://github.com/iojs/io.js/pull/501
Reviewed-By: Bert Belder <bertbelder@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>

test/parallel/test-debug-signal-cluster.js

@@ -2,12 +2,10 @@ var common = require('../common');
 var assert = require('assert');
 var spawn = require('child_process').spawn;
 
-var port = common.PORT + 42;
-var args = ['--debug-port=' + port,
-            common.fixturesDir + '/clustered-server/app.js'];
-var options = { stdio: ['inherit', 'inherit', 'pipe', 'ipc'] };
-var child = spawn(process.execPath, args, options);
-
+var args = [ common.fixturesDir + '/clustered-server/app.js' ];
+var child = spawn(process.execPath, args, {
+  stdio: [ 'pipe', 'pipe', 'pipe', 'ipc' ]
+});
 var outputLines = [];
 var outputTimerId;
 var waitingForDebuggers = false;
@@ -64,11 +62,11 @@ process.on('exit', function onExit() {
 function assertOutputLines() {
   var expectedLines = [
     'Starting debugger agent.',
-    'Debugger listening on port ' + (port + 0),
+    'Debugger listening on port ' + 5858,
     'Starting debugger agent.',
-    'Debugger listening on port ' + (port + 1),
+    'Debugger listening on port ' + 5859,
     'Starting debugger agent.',
-    'Debugger listening on port ' + (port + 2),
+    'Debugger listening on port ' + 5860,
   ];
 
   // Do not assume any particular order of output messages,