Update how we create our MCSymbolizer to keep working correctly
on arm64 binaries after the llvm r206063 changes.  
Patch written by Jim Ingham and Lang Hames.
<rdar://problem/16935671> 


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@209051 91177308-0d34-0410-b5e6-96231b3b80d8