Do not count invocations but usage of a function, i.e., increment a function's counter at IC calls …

runtime/vm/code_generator_x64.h

 // Copyright (c) 2011, 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 VM_CODE_GENERATOR_X64_H_
 #define VM_CODE_GENERATOR_X64_H_
 
 #ifndef VM_CODE_GENERATOR_H_
 #error Do not include code_generator_x64.h directly; use code_generator.h.
 #endif
@@ skipping 105 matching lines @@
   // Treat the first 'num_arguments - num_names' arguments as positional and
   // treat the following 'num_names' arguments as named optional arguments.
   static const Array& ArgumentsDescriptor(
       int num_arguments,
       const Array& optional_arguments_names);
 
   virtual bool IsOptimizing() const {
     return false;
   }
 
-  virtual void CountBackwardLoop();
+  void GenerateReturnEpilog(ReturnNode* node);
 
-  void GenerateReturnEpilog(ReturnNode* node);
+  // Return true if the VM may optimize functions.
+  static bool CanOptimize();
 
  private:
   // TODO(srdjan): Remove the friendship once the two compilers are properly
   // structured.
   friend class OptimizingCodeGenerator;
 
   // Forward declarations.
   class DescriptorList;
   class HandlerList;
 
@@ skipping 84 matching lines @@
   DescriptorList* pc_descriptors_list_;
   HandlerList* exception_handlers_list_;
   int try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(CodeGenerator);
 };
 
 }  // namespace dart
 
 #endif  // VM_CODE_GENERATOR_X64_H_