lib: run microtasks before ticks

This resolve multiple timing issues related to promises
and nextTick. As well as resolving zaldo in promise only
code, i.e. our current best practice of using process.nextTick
will always apply and work.

Refs: nodejs#51156
Refs: nodejs#51156 (comment)
Refs: nodejs#51114
Refs: nodejs#51070
Refs: nodejs#51156

PR-URL: nodejs#51267

lib/internal/process/task_queues.js

@@ -41,6 +41,7 @@ const {
 
 const { AsyncResource } = require('async_hooks');
 
+let experimentalTaskOrdering;
 // *Must* match Environment::TickInfo::Fields in src/env.h.
 const kHasTickScheduled = 0;
 
@@ -65,8 +66,16 @@ function runNextTicks() {
 }
 
 function processTicksAndRejections() {
+  if (experimentalTaskOrdering === undeifned) {
+    const { getOptionValue } = require('internal/options');
+    experimentalTaskOrdering = getOptionValue('--experimental-task-ordering');
+  }
+
   let tock;
   do {
+    if (experimentalTaskOrdering) {
+      runMicrotasks();
+    }
     while ((tock = queue.shift()) !== null) {
       const asyncId = tock[async_id_symbol];
       emitBefore(asyncId, tock[trigger_async_id_symbol], tock);
@@ -92,7 +101,9 @@ function processTicksAndRejections() {
 
       emitAfter(asyncId);
     }
-    runMicrotasks();
+    if (!experimentalTaskOrdering) {
+      runMicrotasks();
+    }
   } while (!queue.isEmpty() || processPromiseRejections());
   setHasTickScheduled(false);
   setHasRejectionToWarn(false);