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

test/mjsunit/shared-function-tier-up-ignition.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: --mark-shared-functions-for-tier-up --allow-natives-syntax --ignition-staging --no-turbo
+// Flags: --mark-shared-functions-for-tier-up --allow-natives-syntax
+// Flags: --ignition-staging --no-turbo
+// Flags: --crankshaft --no-always-opt
 
 (function() {
   var sum = 0;
   var i = 0;
   for (var i = 0; i < 5; ++i) {
     var f = function(x) {
       return 2 * x;
     }
     sum += f(i);
 
@@ skipping 16 matching lines @@
       assertEquals(2, %GetOptimizationStatus(f));
 
       // Run two more times (i = 2, 3), then tier-up to optimized.
       %OptimizeFunctionOnNextCall(f);
     } else if (i == 4) {
       // Tier-up at i = 4 should now go up to crankshaft.
       assertEquals(1, %GetOptimizationStatus(f));
     }
   }
 })()