Fix the NACL_INSTR_* names that I just checked in to NACL_INSTR_ARM_*, as suggested by mseaborn.

tests/dynamic_code_loading/dyncode_demand_alloc_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 <nacl/nacl_dyncode.h>
 
 #include "native_client/src/include/arm_sandbox.h"
 #include "native_client/tests/dynamic_code_loading/dynamic_segment.h"
 
 
 #if defined(__i386__) || defined(__x86_64__)
 uint8_t halts = 0xf4; /* HLT */
 #elif defined(__arm__)
-uint32_t halts = NACL_INSTR_HALT_FILL;
+uint32_t halts = NACL_INSTR_ARM_HALT_FILL;
 #else
 # error "Unknown arch"
 #endif
 
 
 void load_into_page(uint8_t *dest) {
   uint8_t buf[32];
   int rc;
   uint8_t *ptr;
 
@@ skipping 25 matching lines @@
   load_into_page(dyncode + DYNAMIC_CODE_PAGE_SIZE * 2);
 
   printf("Attempting to read from unallocated dyncode page.  "
          "This should fault...\n");
   fprintf(stderr, "** intended_exit_status=untrusted_segfault\n");
   value = dyncode[DYNAMIC_CODE_PAGE_SIZE];
   printf("Failed: Dynamic code page was readable and contained the "
          "byte 0x%x.\n", value);
   return 1;
 }