Add JSBuiltinReducer for inlining well-known builtins.

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 486 matching lines @@
     "src/compiler/graph-visualizer.cc",
     "src/compiler/graph-visualizer.h",
     "src/compiler/graph.cc",
     "src/compiler/graph.h",
     "src/compiler/instruction-codes.h",
     "src/compiler/instruction-selector-impl.h",
     "src/compiler/instruction-selector.cc",
     "src/compiler/instruction-selector.h",
     "src/compiler/instruction.cc",
     "src/compiler/instruction.h",
+    "src/compiler/js-builtin-reducer.cc",
+    "src/compiler/js-builtin-reducer.h",
     "src/compiler/js-context-specialization.cc",
     "src/compiler/js-context-specialization.h",
     "src/compiler/js-generic-lowering.cc",
     "src/compiler/js-generic-lowering.h",
     "src/compiler/js-graph.cc",
     "src/compiler/js-graph.h",
     "src/compiler/js-inlining.cc",
     "src/compiler/js-inlining.h",
     "src/compiler/js-operator.h",
     "src/compiler/js-typed-lowering.cc",
@@ skipping 871 matching lines @@
     deps = [
       ":v8_base",
       ":v8_nosnapshot",
     ]
   }
 
   direct_dependent_configs = [ ":external_config" ]
 }
 
 }