[libunwind] [Libunwind] Don't XFAIL tests with msan (PR #120013)

[Louis Dionne via cfe-commits]

ldionne wrote:

Rebased onto `main` to re-trigger CI, which should solve the errors you were seeing.

I don't remember why these `XFAIL`s were added, but if the CI passes with them removed, I'm happy.

https://github.com/llvm/llvm-project/pull/120013