[MIPS] Make validator allow only two load patterns via $t8

src/trusted/validator_mips/validation-report.py

 #!/usr/bin/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 sys
 import os
 import textwrap
@@ skipping 33 matching lines @@
         'kProblemPatternCrossesBundle': ['This instruction is part of a '
             'sequence that must execute in full, but it spans a bundle edge '
             '-- so an indirect branch may target it',
             1, 1],
         'kProblemBranchInvalidDest': ['This branch targets a location that is '
             'outside of the application\'s executable code, over 256 MB',
             0, 0],
         'kProblemUnsafeLoadStore': ['This load/store instruction is not '
             'preceded by a valid store mask instruction',
             1, 0],
+        'kProblemUnsafeLoadStoreThreadPointer': ['This is not a valid '
+            'load/store instruction for accessing thread pointer.',
+            0, 0],
         'kProblemUnsafeJumpRegister': ['This indirect jump instruction is not '
             'preceded by a valid jump mask instruction',
             1, 0],
         'kProblemUnsafeDataWrite': ['This instruction affects a register that '
             'must contain a valid data-region address (sp), but is not '
             'followed by a valid store mask instruction',
             0, 1],
         'kProblemReadOnlyRegister': ['This instruction changes the contents of'
             ' read-only register',
             0, 0],
@@ skipping 56 matching lines @@
         return 1
     for line in sys.stdin:
         if line.startswith('ncval: '):
             line = line[7:].strip()
             _explain_problem(sys.argv[1], *_parse_report(line))
     return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))