[Interpreter] Introduce IncStub and DecStub.

src/interpreter/interpreter.h

Index: src/interpreter/interpreter.h
diff --git a/src/interpreter/interpreter.h b/src/interpreter/interpreter.h
index 56c3b08cdda21b5c74364e3483d0922ec2bc38e8..fe9fcdea7bb3f304ed99e893ba031e6f357857cb 100644
--- a/src/interpreter/interpreter.h
+++ b/src/interpreter/interpreter.h
@@ -81,9 +81,8 @@ class Interpreter {
   template <class Generator>
   void DoBinaryOp(InterpreterAssembler* assembler);
 
-  // Generates code to perform the count operations via |function_id|.
-  void DoCountOp(Runtime::FunctionId function_id,
-                 InterpreterAssembler* assembler);
+  // Generates code to perform the count operations via |callable|.
+  void DoCountOp(Callable callable, InterpreterAssembler* assembler);
 
   // Generates code to perform the comparison operation associated with
   // |compare_op|.
@@ -128,7 +127,7 @@ class Interpreter {
   // Generates code to perform a type conversion.
   void DoTypeConversionOp(Callable callable, InterpreterAssembler* assembler);
 
-  // Generates code ro create a literal via |function_id|.
+  // Generates code to create a literal via |function_id|.
   void DoCreateLiteral(Runtime::FunctionId function_id,
                        InterpreterAssembler* assembler);