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

test/mjsunit/regress/wasm/regression-02256b.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: --random-seed=891196975 --expose-gc --allow-natives-syntax
 // Flags: --gc-interval=207 --stress-compaction --validate-asm
+// Flags: --crankshaft --no-always-opt
 //
 // /v8/test/mjsunit/wasm/grow-memory.js
 // /v8/test/mjsunit/regress/regress-540.js
 // /v8/test/mjsunit/regress/wasm/regression-02862.js
 // /v8/test/mjsunit/regress/regress-2813.js
 // /v8/test/mjsunit/regress/regress-323845.js
 // Begin stripped down and modified version of mjsunit.js for easy minimization in CF.
 
 function MjsUnitAssertionError(message) {}
 MjsUnitAssertionError.prototype.toString = function() {
@@ skipping 476 matching lines @@
 try {
     __f_33();
     __f_33();
     __f_33();
     %OptimizeFunctionOnNextCall(__f_33);
     __f_33();
     gc();
 } catch (e) {
     print("Caught: " + e);
 }