[MIPS] Support for building tests for MIPS

tests/thread_capture/nacl_thread_capture_test_injection_test.c

 /*
  * 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.
  */
 
 #include <signal.h>
 #include <stdio.h>
 #include <string.h>
 #if !NACL_ANDROID
@@ skipping 26 matching lines @@
 # if NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86
 #  if NACL_BUILD_SUBARCH == 32
   faulting_pc = ucp->uc_mcontext.gregs[REG_EIP];
 #  elif NACL_BUILD_SUBARCH == 64
   faulting_pc = ucp->uc_mcontext.gregs[REG_RIP];
 #  else
 #   error "128-bit version of x86?!?"
 #  endif
 # elif NACL_ARCH(NACL_BUILD_ARCH) == NACL_arm
   faulting_pc = ucp->uc_mcontext.arm_pc;
+# elif NACL_ARCH(NACL_BUILD_ARCH) == NACL_mips
+  faulting_pc = ucp->uc_mcontext.pc;
 # else
 #  error "how do i get the PC on this cpu architecture?"
 # endif
 #elif NACL_OSX
 # if NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86
 #  if NACL_BUILD_SUBARCH == 32
   /* typeof(ucp->uc_mcontext) is struct __darwin_mcontext32 *. */
   faulting_pc = ucp->uc_mcontext->__ss.__eip;
 #  else
   faulting_pc = ucp->uc_mcontext->__ss.__rip;
@@ skipping 42 matching lines @@
 static struct NaClTestInjectionTable const g_test_injection_functions = {
   NaClInjectThreadCaptureSyscall,  /* ChangeTrampolines */
   NaClSetSignalHandler,  /* BeforeMainThreadLaunches */
 };
 
 int main(int argc, char **argv) {
   NaClTestInjectionSetInjectionTable(&g_test_injection_functions);
   (void) NaClSelLdrMain(argc, argv);
   return 1;  /* fail! */
 }