Serializer: move to a subfolder and clean up includes.

tools/external-reference-check.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 import re
 import os
 import sys
 
 DECLARE_FILE = "src/assembler.h"
-REGISTER_FILE = "src/serialize.cc"
+REGISTER_FILE = "src/snapshot/serialize.cc"
 DECLARE_RE = re.compile("\s*static ExternalReference ([^(]+)\(")
 REGISTER_RE = re.compile("\s*Add\(ExternalReference::([^(]+)\(")
 
 WORKSPACE = os.path.abspath(os.path.join(os.path.dirname(sys.argv[0]), ".."))
 
 # Ignore those.
 BLACKLISTED = [
   "page_flags",
   "math_exp_constants",
   "math_exp_log_table",
@@ skipping 12 matching lines @@
 def Main():
   declarations = Find(DECLARE_FILE, DECLARE_RE)
   registrations = Find(REGISTER_FILE, REGISTER_RE)
   difference = list(set(declarations) - set(registrations) - set(BLACKLISTED))
   for reference in difference:
     print("Declared but not registered: ExternalReference::%s" % reference)
   return len(difference) > 0
 
 if __name__ == "__main__":
   sys.exit(Main())