lldb AArch64 should be listed as yet another 64-bit architecture in HostInfoBase.

See http://reviews.llvm.org/D5070.

Change by Paul Osmialowski.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@216556 91177308-0d34-0410-b5e6-96231b3b80d8