[lld] [llvm] [LLD][MachO] make InterfaceFile::symbols iteration order deterministic (PR #97615)

[Cyndy Ishida via llvm-commits]

cyndyishida wrote:

While I agree the underlying non-determinism should be fixed, I don't think we should be using `std::map` instead. This is something I've profiled in the past and there's a considerable slowdown for operations that query symbols that can be represented as a tbd file. 

https://github.com/llvm/llvm-project/pull/97615