ARM64: Enable low level profiling.

tools/ll_prof.py

 #!/usr/bin/env python
 #
 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 333 matching lines @@
     return snapshot_pos_to_name
 
 
 class LogReader(object):
   """V8 low-level (binary) log reader."""
 
   _ARCH_TO_POINTER_TYPE_MAP = {
     "ia32": ctypes.c_uint32,
     "arm": ctypes.c_uint32,
     "mips": ctypes.c_uint32,
-    "x64": ctypes.c_uint64
+    "x64": ctypes.c_uint64,
+    "arm64": ctypes.c_uint64
   }
 
   _CODE_CREATE_TAG = "C"
   _CODE_MOVE_TAG = "M"
   _CODE_DELETE_TAG = "D"
   _SNAPSHOT_POSITION_TAG = "P"
   _CODE_MOVING_GC_TAG = "G"
 
   def __init__(self, log_name, code_map, snapshot_pos_to_name):
     self.log_file = open(log_name, "r")
@@ skipping 637 matching lines @@
       PrintTicks(optimized_ticks, ticks, "ticks in optimized code")
       PrintTicks(generated_ticks, ticks, "ticks in other lazily compiled code")
       PrintTicks(v8_internal_ticks, ticks, "ticks in v8::internal::*")
       print "%10d total symbols" % len([c for c in code_map.AllCode()])
       print "%10d used symbols" % len([c for c in code_map.UsedCode()])
       print "%9.2fs library processing time" % mmap_time
       print "%9.2fs tick processing time" % sample_time
 
   log_reader.Dispose()
   trace_reader.Dispose()