[MIPS] Make $t8 point to the address of TLS pointers

SConstruct

 #! -*- python -*-
 # Copyright (c) 2012 The Native Client 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 atexit
 import json
 import os
 import platform
 import re
@@ skipping 3543 matching lines @@
     nacl_irt_env.Append(LINKFLAGS=['--pnacl-disable-abi-check'])
 
 # The IRT is C only, don't link with the C++ linker so that it doesn't
 # start depending on the C++ standard library and (in the case of
 # libc++) pthread.
 nacl_irt_env.Replace(LINK=(nacl_irt_env['LINK'].
                            replace('pnacl-clang++', 'pnacl-clang')))
 nacl_irt_env.Replace(LINK=(nacl_irt_env['LINK'].
                            replace('nacl-clang++', 'nacl-clang')))
 
-
-# All IRT code must avoid direct use of the TLS ABI register, which
-# is reserved for user TLS.  Instead, ensure all TLS accesses use a
-# call to __nacl_read_tp, which the IRT code overrides to segregate
-# IRT-private TLS from user TLS. This only applies to mips now, on
-# other platforms we modify the TLS register through tls_edit as a
-# post process.
-if nacl_irt_env.Bit('build_mips32'):
-  nacl_irt_env.Append(LINKFLAGS=['-Wt,-mtls-use-call'])
-
 # TODO(mcgrathr): Clean up uses of these methods.
 def AddLibraryDummy(env, nodes):
   return nodes
 nacl_irt_env.AddMethod(AddLibraryDummy, 'AddLibraryToSdk')
 
 def AddObjectInternal(env, nodes):
   return env.Replicate('${LIB_DIR}', nodes)
 nacl_env.AddMethod(AddObjectInternal, 'AddObjectToSdk')
 nacl_irt_env.AddMethod(AddObjectInternal, 'AddObjectToSdk')
 
@@ skipping 466 matching lines @@
   nacl_env.ValidateSdk()
 
 if BROKEN_TEST_COUNT > 0:
   msg = "There are %d broken tests." % BROKEN_TEST_COUNT
   if GetOption('brief_comstr'):
     msg += " Add --verbose to the command line for more information."
   print msg
 
 # separate warnings from actual build output
 Banner('B U I L D - O U T P U T:')