[llvm] [DA] Fix the Weak Zero SIV tests when the coeff may be zero (PR #183736)

[Sjoerd Meijer via llvm-commits]

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

Thanks, looks like a good fix to me.

Maybe wait a day with merging this to give other folks a chance to leave some comments. 

https://github.com/llvm/llvm-project/pull/183736