[libunwind][ARM] Handle end of stack during unwind

When unwind step reaches the end of the stack that means the force unwind should notify the stop function.
This is not an error, it could mean just the thread is cleaned up completely.

Reviewed By: #libunwind, mstorsjo

Differential Revision: https://reviews.llvm.org/D109856

GitOrigin-RevId: 632acec73776c4d6f7073d6de04ed6b8bfd36e6d
2 files changed