Fix map-constructor-entry-side-effect2 test

Bytecode flushing interferes with IsOptimized expectations.

Bug: v8:7790,v8:11939
Change-Id: I4aaf827cb198d0a93f18e106a95d72b143c79dfc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2999092
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75508}

test/mjsunit/es6/map-constructor-entry-side-effect2.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --opt
+// Flags: --allow-natives-syntax --opt --no-flush-bytecode
 
 function TestMapConstructorEntrySideEffect(ctor) {
   const originalPrototypeSet = ctor.prototype.set;