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

test/mjsunit/es6/block-let-crankshaft.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 462 matching lines @@
   f(i);
   g(i);
 }
 
 %OptimizeFunctionOnNextCall(f);
 %OptimizeFunctionOnNextCall(g);
 
 f(12);
 g(12);
 
-assertTrue(%GetOptimizationStatus(f) != 2);
-assertTrue(%GetOptimizationStatus(g) != 2);
+assertOptimized(f);
+assertOptimized(g);