Fix broken debug build: prevent adding the same cid twice.

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/compiler.h"
 #include "vm/cpu.h"
@@ skipping 146 matching lines @@
 
 // TODO(srdjan): Test/support other number types as well.
 static bool IsNumberCid(intptr_t cid) {
   return (cid == kSmiCid) || (cid == kDoubleCid);
 }
 
 
 // Attempt to build ICData for call using propagated class-ids.
 bool FlowGraphOptimizer::TryCreateICData(InstanceCallInstr* call) {
   ASSERT(call->HasICData());
-  if (call->ic_data()->NumberOfUsedChecks() > 0) {
+  if (call->ic_data()->NumberOfChecks() > 0) {
     // This occurs when an instance call has too many checks, will be converted
     // to megamorphic call.
     return false;
   }
   if (FLAG_warn_on_javascript_compatibility) {
     // Do not make the instance call megamorphic if the callee needs to decode
     // the calling code sequence to lookup the ic data and verify if a warning
     // has already been issued or not.
     // TryCreateICData is only invoked if the ic_data target has not been called
     // yet, so no warning can possibly have been issued.
@@ skipping 8541 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart