Fix GN build after r23442.

BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # TODO(jochen): These will need to be user-settable to support standalone V8
 # builds.
 v8_compress_startup_data = "off"
 v8_deprecation_warnings = false
 v8_enable_disassembler = false
 v8_enable_gdbjit = false
@@ skipping 444 matching lines @@
     "src/code-stubs.cc",
     "src/code-stubs.h",
     "src/code-stubs-hydrogen.cc",
     "src/code.h",
     "src/codegen.cc",
     "src/codegen.h",
     "src/compilation-cache.cc",
     "src/compilation-cache.h",
     "src/compiler/ast-graph-builder.cc",
     "src/compiler/ast-graph-builder.h",
+    "src/compiler/change-lowering.cc",
+    "src/compiler/change-lowering.h",
     "src/compiler/code-generator-impl.h",
     "src/compiler/code-generator.cc",
     "src/compiler/code-generator.h",
     "src/compiler/common-node-cache.h",
     "src/compiler/common-operator.h",
     "src/compiler/control-builders.cc",
     "src/compiler/control-builders.h",
     "src/compiler/frame.h",
     "src/compiler/gap-resolver.cc",
     "src/compiler/gap-resolver.h",
@@ skipping 870 matching lines @@
     deps = [
       ":v8_base",
       ":v8_nosnapshot",
     ]
   }
 
   direct_dependent_configs = [ ":external_config" ]
 }
 
 }