Move bit_cast from base/macros.h to its own header

chromeos/hugepage_text/hugepage_text.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 // Author: Ken Chen <kenchen@google.com>
 //
 // hugepage text library to remap process executable segment with hugepages.
 
 #include "chromeos/hugepage_text/hugepage_text.h"
 
 #include <link.h>
 #include <sys/mman.h>
 
+#include "base/bit_cast.h"
 #include "base/logging.h"
 
 namespace chromeos {
 
 #ifndef MAP_HUGETLB
 #define MAP_HUGETLB 0x40000
 #endif
 
 #ifndef TMPFS_MAGIC
 #define TMPFS_MAGIC 0x01021994
@@ skipping 188 matching lines @@
 
 // Main library function.  This function will iterate all ELF segments and
 // attempt to remap text segment from small page to hugepage.
 // If remapping is successful.  All error conditions are soft fail such that
 // effect will be rolled back and remap operation will be aborted.
 void ReloadElfTextInHugePages(void) {
   dl_iterate_phdr(FilterElfHeader, 0);
 }
 
 }  // namespace chromeos