Extend relocation packing to cover arm64.

tools/relocation_packer/test_data/elf_file_unittest_relocs.cc

 // Copyright 2014 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.
 
 // Test data for packing/unpacking.  When compiled, creates a run of
 // relative relocations.
 //
-// #!/bin/bash
-//
-// # Compile as an arm shared library.
-// /usr/bin/arm-linux-gnueabi-g++ -shared -o /tmp/testdata.so \
-//   elf_file_unittest_relocs.cc
-//
-// # Add a new null .android.rel.dyn section, needed for packing.
-// echo 'NULL' >/tmp/small
-// /usr/bin/arm-linux-gnueabi-objcopy \
-//   --add-section .android.rel.dyn=/tmp/small /tmp/testdata.so
-//
-// # Create packed and unpacked reference files.
-// packer="../../../out_android/Debug/relocation_packer"
-// cp /tmp/testdata.so elf_file_unittest_relocs_packed.so
-// $packer elf_file_unittest_relocs_packed.so
-// cp elf_file_unittest_relocs_packed.so elf_file_unittest_relocs.so
-// $packer -u elf_file_unittest_relocs.so
-//
-// # Clean up.
-// rm /tmp/testdata.so /tmp/small
+// See generate_elf_file_unittest_relocs.sh for instructions on how to build
+// unit test data from this source file.
 
 const int i = 0;
 
 const void* pointer_0 = &i;
 const void* pointer_1 = &i;
 const void* pointer_2 = &i;
 const void* pointer_3 = &i;
 const void* pointer_4 = &i;
 const void* pointer_5 = &i;
 const void* pointer_6 = &i;
@@ skipping 16 matching lines @@
 const void* pointer_23 = &i;
 const void* pointer_24 = &i;
 const void* pointer_25 = &i;
 const void* pointer_26 = &i;
 const void* pointer_27 = &i;
 const void* pointer_28 = &i;
 const void* pointer_29 = &i;
 const void* pointer_30 = &i;
 const void* pointer_31 = &i;
 const void* pointer_32 = &i;