[libunwind] [libunwind][AArch64] Protect PC within libunwind's context. (PR #113368)

[Daniel Kiss via cfe-commits]

DanielKristofKiss wrote:

sorry for the debug here, locally I can't reproduce the test failure( macos m1, same toolchain, same build steps )

https://github.com/llvm/llvm-project/pull/113368