[llvm] llvm-objdump: ensure a MachO symbol isn't STAB before looking up secion (PR #86667)

[Tim Northover via llvm-commits]

TNorthover wrote:

Interesting history, thanks.

I've updated the test to use a YAML input instead. I've not tried reducing it beyond what came out of compiling `int main() {}` though, there are so many brute offsets and sizes I'd almost certainly break something if I tried (and it may not even be detected until later).

https://github.com/llvm/llvm-project/pull/86667