Revert of [tests] Make assertOptimized()/assertUnoptimized() great again.

test/mjsunit/regress/regress-4121.js

Index: test/mjsunit/regress/regress-4121.js
diff --git a/test/mjsunit/regress/regress-4121.js b/test/mjsunit/regress/regress-4121.js
index 46976cc6cf638005d9e10e5c2b3ca500e1460b7c..a175ed9fd2216e16b2106ac8cf5c467e8722e2a4 100644
--- a/test/mjsunit/regress/regress-4121.js
+++ b/test/mjsunit/regress/regress-4121.js
@@ -2,9 +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 --no-always-opt
-
-assertFalse(isAlwaysOptimize());
+// Flags: --allow-natives-syntax
 
 function literals_sharing_test(warmup, optimize) {
   function closure() {
@@ -41,4 +39,10 @@
   literals_sharing_test(warmup, true);
 }
 
-test();
+
+function stress_opt_test() {}
+stress_opt_test();
+if (%GetOptimizationStatus(stress_opt_test) == 2) {
+  // This test is not suitable for --always-opt mode.
+  test();
+}