Apply patch from Alexander Botero-Lowry that adds FreeBSD platform

src/SConscript

 # Copyright 2008 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 37 matching lines @@
     'unicode.cc', 'usage-analyzer.cc', 'utils.cc', 'v8-counters.cc',
     'v8.cc', 'v8threads.cc', 'variables.cc', 'zone.cc'
   ],
   'arch:arm':  ['assembler-arm.cc', 'builtins-arm.cc', 'codegen-arm.cc',
       'cpu-arm.cc', 'disasm-arm.cc', 'frames-arm.cc', 'ic-arm.cc',
       'macro-assembler-arm.cc', 'stub-cache-arm.cc'],
   'arch:ia32': ['assembler-ia32.cc', 'builtins-ia32.cc', 'codegen-ia32.cc',
       'cpu-ia32.cc', 'disasm-ia32.cc', 'frames-ia32.cc', 'ic-ia32.cc',
       'macro-assembler-ia32.cc', 'stub-cache-ia32.cc'],
   'simulator:arm': ['simulator-arm.cc'],
-  'os:linux':  ['platform-linux.cc'],
-  'os:macos':  ['platform-macos.cc'],
-  'os:nullos': ['platform-nullos.cc'],
-  'os:win32':  ['platform-win32.cc'],
+  'os:freebsd': ['platform-freebsd.cc'],
+  'os:linux':   ['platform-linux.cc'],
+  'os:macos':   ['platform-macos.cc'],
+  'os:nullos':  ['platform-nullos.cc'],
+  'os:win32':   ['platform-win32.cc'],
   'mode:release': [],
   'mode:debug': ['objects-debug.cc', 'prettyprinter.cc']
 }
 
 
 D8_FILES = {
   'all': [
     'd8.cc'
   ],
   'console:readline': [
@@ skipping 79 matching lines @@
     libraries_obj = context.ConfigureObject(env, libraries_empty_src, CPPPATH=['.'])
   else:
     snapshot_obj = empty_snapshot_obj
 
   library_objs = [non_snapshot_files, libraries_obj, snapshot_obj]
   return (library_objs, d8_objs)
 
 
 (library_objs, d8_objs) = ConfigureObjectFiles()
 Return('library_objs d8_objs')