test: migrated from Promise chains to Async/Await

PR-URL: #44674
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

test/sequential/test-debugger-restart-message.js

@@ -16,24 +16,22 @@ const startCLI = require('../common/debugger');
   const script = fixtures.path('debugger', 'three-lines.js');
   const cli = startCLI([script]);
 
-  function onFatal(error) {
-    cli.quit();
-    throw error;
-  }
-
   const listeningRegExp = /Debugger listening on/g;
 
-  cli.waitForInitialBreak()
-    .then(() => cli.waitForPrompt())
-    .then(() => {
+  async function onWaitForInitialBreak() {
+    try {
+      await cli.waitForInitialBreak();
+      await cli.waitForPrompt();
       assert.strictEqual(cli.output.match(listeningRegExp).length, 1);
-    })
-    .then(async () => {
+
       for (let i = 0; i < RESTARTS; i++) {
         await cli.stepCommand('restart');
         assert.strictEqual(cli.output.match(listeningRegExp).length, 1);
       }
-    })
-    .then(() => cli.quit())
-    .then(null, onFatal);
+    } finally {
+      await cli.quit();
+    }
+  }
+
+  onWaitForInitialBreak();
 }