<rdar://problem/14262854>

Match up with top’s implementation on recent Cab as API has changed a bit.
Tested the same binary running on Zin as well. Tested ARM binary on iOS as well.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@185017 91177308-0d34-0410-b5e6-96231b3b80d8