Removed SCons warning flags duplication on Windows. It now uses...

SConstruct

 # 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 45 matching lines @@
       'CCFLAGS':      ['-O2']
     },
     'wordsize:64': {
       'CCFLAGS':      ['-m32'],
       'LINKFLAGS':    ['-m32']
     }
   },
   'msvc': {
     'all': {
       'DIALECTFLAGS': ['/nologo'],
-      'WARNINGFLAGS': ['/W3', '/WX', '/wd4355', '/wd4800'],
       'CCFLAGS':      ['$DIALECTFLAGS', '$WARNINGFLAGS'],
       'CXXFLAGS':     ['$CCFLAGS', '/GR-', '/Gy'],
       'CPPDEFINES':   ['WIN32', '_USE_32BIT_TIME_T', 'PCRE_STATIC'],
       'LINKFLAGS':    ['/NOLOGO', '/MACHINE:X86', '/INCREMENTAL:NO',
           '/NXCOMPAT', '/IGNORE:4221'],
       'ARFLAGS':      ['/NOLOGO'],
       'CCPDBFLAGS':   ['/Zi']
     },
     'mode:debug': {
       'CCFLAGS':      ['/Od', '/Gm', '/MTd'],
@@ skipping 449 matching lines @@
 # version of scons.  Also, there's a bug in some revisions that
 # doesn't allow this flag to be set, so we swallow any exceptions.
 # Lovely.
 try:
   SetOption('warn', 'no-deprecated')
 except:
   pass
 
 
 Build()