systems (ios, tvos, watchos). It's a simple format to use now that
I have i386/x86_64 supported already.
The unwind instructions are only valid at call sites -- that is,
when lldb is unwinding a frame in the middle of the stack. It
cannot be used for the currently executing frame; it has no information
about prologues/epilogues/etc.
<rdar://problem/12062336>
llvm-svn: 270658