[Lldb-commits] [lldb] [lldb/aarch64] Fix unwinding when signal interrupts a leaf function (PR #91321)

[Jason Molenda via lldb-commits]

https://github.com/jasonmolenda approved this pull request.

This looks good to me, I know there are other codepaths that handle this correctly, where we can backtrace out of a frameless function that faults into a trap handler and we have the entire register state available in the trap handler.  

Looking at this, I'm a little uncertain why we have `m_behaves_like_zeroth_frame` and `m_all_registers_available` which are both set to true under the same conditions, and then we sometimes use `m_behaves_like_zeroth_frame`, sometimes `m_all_registers_available `, and sometimes call `RegisterContextUnwind::BehavesLikeZerothFrame` which has a redundant check if the frame number is 0, sigh.  Looks like some accumulated nonsense that you shouldn't have to deal with in this patch.

https://github.com/llvm/llvm-project/pull/91321