[llvm] [DWARFLinker] Handle empty sequences when processing `DW_AT_LLVM_stmt_sequence` attributes (PR #132875)

[Jonas Devlieghere via llvm-commits]

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JDevlieghere wrote:

I wasn't aware of `update_test_body.py` and I haven't tried it to generate Mach-Os for dsymutil test, but I'm happy to go with a standardized approach as I agree that the current ad-hoc approach is rather painful. 

My preferred approach would be to use yaml for the object files (with yaml2obj) and for the debug map (which you can dump with `dsymutil`). I think that's the most readable/auditable, but it's also a pain to do by hand. Maybe the sweet spot is to have a script similar to `update_test_body.py` specifically for the DWARF linker? 

Anyway, for this PR I think it's fine to stick with (1) as that's the established way of doing this while we settle on how to go forward. I always (try to) include instructions and source code to regenerate the test so maybe we can use some of the existing ones to test the approach. 


https://github.com/llvm/llvm-project/pull/132875