[llvm] [ASan] Prevent assert from scalable vectors in FunctionStackPoisoner. (PR #155357)

[Thurston Dang via llvm-commits]

thurstond wrote:

> Good point! I hadn't thought of the two different meanings. I've updated the title. Thanks for the quick review.

Thank you!

https://github.com/llvm/llvm-project/pull/155357