[runtime] Move binary operator fallbacks into the runtime.

src/interpreter/interpreter.h

Index: src/interpreter/interpreter.h
diff --git a/src/interpreter/interpreter.h b/src/interpreter/interpreter.h
index f4237b3ad2cf13d74c811bd71f539176cdb580c7..1e4ca5cdb80b1ef5e173dea1165d8a3c4741f8c3 100644
--- a/src/interpreter/interpreter.h
+++ b/src/interpreter/interpreter.h
@@ -11,6 +11,7 @@
 #include "src/base/macros.h"
 #include "src/builtins.h"
 #include "src/interpreter/bytecodes.h"
+#include "src/runtime/runtime.h"
 
 namespace v8 {
 namespace internal {
@@ -48,8 +49,8 @@ class Interpreter {
   BYTECODE_LIST(DECLARE_BYTECODE_HANDLER_GENERATOR)
 #undef DECLARE_BYTECODE_HANDLER_GENERATOR
 
-  // Generates code to perform the binary operations via |binop_builtin|.
-  void DoBinaryOp(int builtin_context_index,
+  // Generates code to perform the binary operations via |function_id|.
+  void DoBinaryOp(Runtime::FunctionId function_id,
                   compiler::InterpreterAssembler* assembler);
 
   // Generates code to perform a property load via |ic|.