[interpreter] Split bytecode generation out of interpreter.cc

src/interpreter/interpreter-generator.h

+// Copyright 2017 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_GENERATOR_H_
+#define V8_INTERPRETER_INTERPRETER_GENERATOR_H_
+
+#include "src/interpreter/bytecode-operands.h"
+#include "src/interpreter/bytecodes.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+extern Handle<Code> GenerateBytecodeHandler(Isolate* isolate, Bytecode bytecode,
+                                            OperandScale operand_scale);
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTERPRETER_INTERPRETER_GENERATOR_H_