[interpreter] Introduce bytecode generation pipeline.

test/unittests/interpreter/bytecode-peephole-optimizer-unittest.cc

-// Copyright 2014 the V8 project authors. All rights reserved.
+// Copyright 2016 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.
 
-#include "test/unittests/compiler/instruction-selector-unittest.h"
+#include "src/v8.h"
 
 namespace v8 {
 namespace internal {
-namespace compiler {}  // namespace compiler
+namespace interpreter {
+
+// TODO(oth): Tests of peephole optimizations.
+
+}  // namespace interpreter
 }  // namespace internal
 }  // namespace v8