[tests] Cleanup tests that use assertOptimized()/assertUnoptimized().

test/mjsunit/es6/array-iterator-turbo.js

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --turbo --turbo-escape --allow-natives-syntax
+// Flags: --turbo --turbo-escape --allow-natives-syntax --no-always-opt
 
 "use strict";
 
 const kDeoptimized = 2;
 const kTurbofanned = 7;
 const kInterpreted = 8;
 
 function GetOptimizationStatus(fn) {
   let status = %GetOptimizationStatus(fn);
   switch (status) {
@@ skipping 218 matching lines @@
       %ArrayBufferNeuter(clone.buffer);
       assertThrows(() => sum(clone), TypeError);
     }
   }
 };
 
 for (let name of Object.keys(tests)) {
   let test = tests[name];
   test();
 }