test: make cluster tests more time tolerant

Port f3f4e28216
to master, updating to guard changes for AIX as requested

PR-URL: https://github.com/nodejs/node/pull/2891
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

test/parallel/test-cluster-master-error.js

@@ -93,7 +93,12 @@ if (cluster.isWorker) {
     existMaster = !!code;
 
     // Give the workers time to shut down
-    setTimeout(checkWorkers, 200);
+    var timeout = 200;
+    if (common.isAix) {
+      // AIX needs more time due to default exit performance
+      timeout = 1000;
+    }
+    setTimeout(checkWorkers, timeout);
 
     function checkWorkers() {
       // When master is dead all workers should be dead to

test/parallel/test-cluster-master-kill.js

@@ -59,9 +59,14 @@ if (cluster.isWorker) {
     assert.equal(code, 0);
 
     // check worker process status
+    var timeout = 200;
+    if (common.isAix) {
+      // AIX needs more time due to default exit performance
+      timeout = 1000;
+    }
     setTimeout(function() {
       alive = isAlive(pid);
-    }, 200);
+    }, timeout);
   });
 
   process.once('exit', function() {