Make fast tls the default

SConstruct

 # Copyright 2011 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 51 matching lines @@
     },
     'objectprint:on': {
       'CPPDEFINES':   ['OBJECT_PRINT'],
     },
     'debuggersupport:on': {
       'CPPDEFINES':   ['ENABLE_DEBUGGER_SUPPORT'],
     },
     'inspector:on': {
       'CPPDEFINES':   ['INSPECTOR'],
     },
-    'fasttls:on': {
-      'CPPDEFINES':   ['V8_FAST_TLS'],
+    'fasttls:off': {
+      'CPPDEFINES':   ['V8_NO_FAST_TLS'],
     },
     'liveobjectlist:on': {
       'CPPDEFINES':   ['ENABLE_DEBUGGER_SUPPORT', 'INSPECTOR',
                        'LIVE_OBJECT_LIST', 'OBJECT_PRINT'],
     }
   },
   'gcc': {
     'all': {
       'CCFLAGS':      ['$DIALECTFLAGS', '$WARNINGFLAGS'],
       'CXXFLAGS':     ['-fno-rtti', '-fno-exceptions'],
@@ skipping 1380 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()