[Interpreter] Add support for for count operations.

src/interpreter/interpreter.h

 // Copyright 2015 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.
 
 #ifndef V8_INTERPRETER_INTERPRETER_H_
 #define V8_INTERPRETER_INTERPRETER_H_
 
 // Clients of this interface shouldn't depend on lots of interpreter internals.
 // Do not include anything from src/interpreter other than
 // src/interpreter/bytecodes.h here!
@@ skipping 36 matching lines @@
 // Bytecode handler generator functions.
 #define DECLARE_BYTECODE_HANDLER_GENERATOR(Name, ...) \
   void Do##Name(compiler::InterpreterAssembler* assembler);
   BYTECODE_LIST(DECLARE_BYTECODE_HANDLER_GENERATOR)
 #undef DECLARE_BYTECODE_HANDLER_GENERATOR
 
   // Generates code to perform the binary operations via |function_id|.
   void DoBinaryOp(Runtime::FunctionId function_id,
                   compiler::InterpreterAssembler* assembler);
 
+  // Generates code to perform the count operations via |function_id|.
+  void DoCountOp(Runtime::FunctionId function_id,
+                 compiler::InterpreterAssembler* assembler);
+
   // Generates code to perform the comparison operation associated with
   // |compare_op|.
   void DoCompareOp(Token::Value compare_op,
                    compiler::InterpreterAssembler* assembler);
 
   // Generates code to perform a property load via |ic|.
   void DoPropertyLoadIC(Callable ic, compiler::InterpreterAssembler* assembler);
 
   // Generates code to perform a property store via |ic|.
   void DoPropertyStoreIC(Callable ic,
                          compiler::InterpreterAssembler* assembler);
 
   // Generates code ro create a literal via |function_id|.
   void DoCreateLiteral(Runtime::FunctionId function_id,
                        compiler::InterpreterAssembler* assembler);
 
   bool IsInterpreterTableInitialized(Handle<FixedArray> handler_table);
 
   Isolate* isolate_;
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_H_