[libunwind] [libunwind][Haiku] Fix signal frame unwinding (PR #135367)

[Trung Nguyen via cfe-commits]

trungnt2910 wrote:

> Does it build on r1beta5?

Theoretically yes, since I did not require any new Haiku nightly feature for tge implementation.

The unwinding might not fully work due to missing CFE information in `libroot`, in this case for `_kern_send_signal`.



https://github.com/llvm/llvm-project/pull/135367