Address comments on Issue 258563004.

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 3665 matching lines @@
 // If type tests specified by 'ic_data' do not depend on type arguments,
 // return mapping cid->result in 'results' (i : cid; i + 1: result).
 // If all tests yield the same result, return it otherwise return Bool::null.
 // If no mapping is possible, 'results' is empty.
 // An instance-of test returning all same results can be converted to a class
 // check.
 RawBool* FlowGraphOptimizer::InstanceOfAsBool(
     const ICData& ic_data,
     const AbstractType& type,
     ZoneGrowableArray<intptr_t>* results) const {
-  results->Clear();
+  ASSERT(results->is_empty());
   ASSERT(ic_data.NumArgsTested() == 1);  // Unary checks only.
   if (!type.IsInstantiated() || type.IsMalformedOrMalbounded()) {
     return Bool::null();
   }
   const Class& type_class = Class::Handle(type.type_class());
   const intptr_t num_type_args = type_class.NumTypeArguments();
   if (num_type_args > 0) {
     // Only raw types can be directly compared, thus disregarding type
     // arguments.
     const intptr_t num_type_params = type_class.NumTypeParameters();
@@ skipping 114 matching lines @@
     results->Add((*results)[results->length() - 2]);
     for (intptr_t i = results->length() - 3; i > 1; --i) {
       (*results)[i] = (*results)[i - 2];
     }
     (*results)[0] = kSmiCid;
     (*results)[1] = smi_is_subtype;
   }
 
   ASSERT(type.IsInstantiated() && !type.IsMalformedOrMalbounded());
   ASSERT(results->length() >= 2);
-  // const Class& type_class = Class::Handle(type.type_class())
   if (type.IsIntType()) {
     ASSERT((*results)[0] == kSmiCid);
     TryAddTest(results, kMintCid, true);
     TryAddTest(results, kBigintCid, true);
     // Cannot deoptimize since all tests returning true have been added.
     return false;
   }
 
   return true;  // May deoptimize since we have not identified all 'true' tests.
 }
@@ skipping 5321 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *slots);
   }
 }
 
 
 }  // namespace dart