[libunwind] [libunwind] Introduce _LIBUNWIND_TRACE_DWARF_EVAL for increased baremetal friendliness (PR #72040)

[Louis Dionne via cfe-commits]

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

This looks like an improvement to me. I have a comment/question about the `stdio.h` include which is now dangling, but apart from that I'm happy with the patch.

https://github.com/llvm/llvm-project/pull/72040