ICData::NumberOfChecks is O(n) so don't call it in loops

runtime/vm/intermediate_language.h

 // 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.
 
 #ifndef RUNTIME_VM_INTERMEDIATE_LANGUAGE_H_
 #define RUNTIME_VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 2775 matching lines @@
   PolymorphicInstanceCallInstr(InstanceCallInstr* instance_call,
                                const ICData& ic_data,
                                bool with_checks,
                                bool complete)
       : TemplateDefinition(instance_call->deopt_id()),
         instance_call_(instance_call),
         ic_data_(ic_data),
         with_checks_(with_checks),
         complete_(complete) {
     ASSERT(instance_call_ != NULL);
-    ASSERT(ic_data.NumberOfChecks() > 0);
+    ASSERT(!ic_data.NumberOfChecksIs(0));
   }
 
   InstanceCallInstr* instance_call() const { return instance_call_; }
   bool with_checks() const { return with_checks_; }
   void set_with_checks(bool b) { with_checks_ = b; }
   bool complete() const { return complete_; }
   virtual TokenPosition token_pos() const {
     return instance_call_->token_pos();
   }
 
@@ skipping 5236 matching lines @@
   LocationSummary* Name::MakeLocationSummary(Zone* zone, bool opt) const {     \
     UNIMPLEMENTED();                                                           \
     return NULL;                                                               \
   }                                                                            \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_INTERMEDIATE_LANGUAGE_H_