core: Remove the nextTick for running the main file

Not necessary, since we can handle the error properly on the first tick
now, even if there are event listeners, etc.

Additionally, this removes the unnecessary "_needTickCallback" from
startup, since Module.loadMain() will kick off a nextTick callback right
after it runs the main module.

Fix #4856

lib/module.js

@@ -495,6 +495,8 @@ Module._extensions['.node'] = process.dlopen;
 Module.runMain = function() {
   // Load the main module--the command line argument.
   Module._load(process.argv[1], null, true);
+  // Handle any nextTicks added in the first tick of the program
+  process._tickCallback();
 };
 
 Module._initPaths = function() {

src/node.js

@@ -114,10 +114,8 @@
         setTimeout(Module.runMain, debugTimeout);
 
       } else {
-        // REMOVEME: nextTick should not be necessary. This hack to get
-        // test/simple/test-exception-handler2.js working.
         // Main entry point into most programs:
-        process.nextTick(Module.runMain);
+        Module.runMain();
       }
 
     } else {
@@ -156,8 +154,6 @@
         });
       }
     }
-
-    process._needTickCallback();
   }
 
   startup.globalVariables = function() {

test/message/error_exit.out

@@ -9,6 +9,6 @@ AssertionError: 1 == 2
     at Object.Module._extensions..js (module.js:*:*)
     at Module.load (module.js:*:*)
     at Function.Module._load (module.js:*:*)
-    at Module.runMain (module.js:*:*)
-    at _tickCallback (node.js:*:*)
-    at process._tickFromSpinner (node.js:*:*)
+    at Function.Module.runMain (module.js:*:*)
+    at startup (node.js:*:*)
+    at node.js:*:*

test/message/max_tick_depth.out

@@ -7,8 +7,8 @@ tick 15
 tick 14
 tick 13
 tick 12
-(node) warning: Recursive process.nextTick detected. This will break in the next version of node. Please use setImmediate for recursive deferral.
 tick 11
+(node) warning: Recursive process.nextTick detected. This will break in the next version of node. Please use setImmediate for recursive deferral.
 tick 10
 tick 9
 tick 8
@@ -18,6 +18,6 @@ tick 5
 tick 4
 tick 3
 tick 2
-(node) warning: Recursive process.nextTick detected. This will break in the next version of node. Please use setImmediate for recursive deferral.
 tick 1
+(node) warning: Recursive process.nextTick detected. This will break in the next version of node. Please use setImmediate for recursive deferral.
 tick 0

test/message/max_tick_depth_trace.out

@@ -7,13 +7,15 @@ tick 15
 tick 14
 tick 13
 tick 12
+tick 11
 Trace: (node) warning: Recursive process.nextTick detected. This will break in the next version of node. Please use setImmediate for recursive deferral.
     at maxTickWarn (node.js:*:*)
-    at process.nextTick (node.js:*:*
+    at process.nextTick (node.js:*:*)
     at f (*test*message*max_tick_depth_trace.js:*:*)
-    at _tickCallback (node.js:*:*)
-    at process._tickFromSpinner (node.js:*:*)
-tick 11
+    at process._tickCallback (node.js:*:*)
+    at Function.Module.runMain (module.js:*:*)
+    at startup (node.js:*:*)
+    at node.js:*:*
 tick 10
 tick 9
 tick 8
@@ -23,11 +25,11 @@ tick 5
 tick 4
 tick 3
 tick 2
+tick 1
 Trace: (node) warning: Recursive process.nextTick detected. This will break in the next version of node. Please use setImmediate for recursive deferral.
     at maxTickWarn (node.js:*:*)
-    at process.nextTick (node.js:*:*
+    at process.nextTick (node.js:*:*)
     at f (*test*message*max_tick_depth_trace.js:*:*)
     at _tickCallback (node.js:*:*)
     at process._tickFromSpinner (node.js:*:*)
-tick 1
 tick 0

test/message/nexttick_throw.out

@@ -1,7 +1,10 @@
+
 *test*message*nexttick_throw.js:*
         undefined_reference_error_maker;
         ^
 ReferenceError: undefined_reference_error_maker is not defined
     at *test*message*nexttick_throw.js:*:*
-    at _tickCallback (node.js:*:*)
-    at process._tickFromSpinner (node.js:*:*)
+    at process._tickCallback (node.js:*:*)
+    at Function.Module.runMain (module.js:*:*)
+    at startup (node.js:*:*)
+    at node.js:*:*

test/message/undefined_reference_in_new_context.out

@@ -9,7 +9,7 @@ ReferenceError: foo is not defined
     at Module._compile (module.js:*)
     at *..js (module.js:*)
     at Module.load (module.js:*)
-    at *._load (module.js:*)
-    at Module.runMain (module.js:*)
-    at _tickCallback (node.js:*)
-    at *._tickFromSpinner (node.js:*)
+    at Function.Module._load (module.js:*:*)
+    at Function.Module.runMain (module.js:*:*)
+    at startup (node.js:*:*)
+    at node.js:*:*

test/simple/test-domain.js

@@ -110,6 +110,12 @@ d.on('error', function(er) {
       assert.ok(!er.domainBound);
       break;
 
+    case 'nextTick execution loop':
+      assert.equal(er.domain, d);
+      assert.ok(!er.domainEmitter);
+      assert.ok(!er.domainBound);
+      break;
+
     default:
       console.error('unexpected error, throwing %j', er.message, er);
       throw er;
@@ -127,6 +133,18 @@ process.on('exit', function() {
 });
 
 
+
+// revert to using the domain when a callback is passed to nextTick in
+// the middle of a tickCallback loop
+d.run(function() {
+  process.nextTick(function() {
+    throw new Error('nextTick execution loop');
+  });
+});
+expectCaught++;
+
+
+
 // catch thrown errors no matter how many times we enter the event loop
 // this only uses implicit binding, except for the first function
 // passed to d.run().  The rest are implicitly bound by virtue of being