Add wrapper library for the nacl_irt_exception_handling IRT interface

tests/exception_test/exception_crash_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 <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "native_client/src/include/nacl/nacl_exception.h"
 #include "native_client/src/trusted/service_runtime/include/sys/nacl_test_crash.h"
 #include "native_client/src/untrusted/nacl/syscall_bindings_trampoline.h"
 
 
-typedef void (*handler_func_t)(struct NaClExceptionContext *context);
-
 char stack_in_rwdata[0x1000];
 
 /*
  * Note that we have to provide an initialiser here otherwise gcc
  * defines this using ".comm" and the variable does not get put into a
  * read-only segment.
  */
 const char stack_in_rodata[0x1000] = "blah";
 
 
 void test_bad_handler(void) {
   /*
    * Use an address that we know contains no valid code, yet is within
    * the code segment range and is well-aligned.  The bottom 64k of
    * address space is never mapped.
    */
-  handler_func_t handler = (handler_func_t) 0x1000;
+  nacl_exception_handler_t handler = (nacl_exception_handler_t) 0x1000;
   int rc = NACL_SYSCALL(exception_handler)(handler, NULL);
   assert(rc == 0);
   fprintf(stderr, "** intended_exit_status=untrusted_segfault\n");
   /* Cause crash. */
   *(volatile int *) 0 = 0;
 }
 
 
 #if defined(__i386__) || defined(__x86_64__)
 
@@ skipping 193 matching lines @@
   TRY_TEST(test_bad_handler);
   TRY_TEST(test_stack_outside_sandbox);
   TRY_TEST(test_stack_in_rwdata);
   TRY_TEST(test_stack_in_rodata);
   TRY_TEST(test_stack_in_code);
   TRY_TEST(test_crash_in_syscall);
 
   fprintf(stderr, "Error: Unknown test: \"%s\"\n", argv[1]);
   return 1;
 }