[llvm] [llvm] Fix __builtin_object_size interaction between Negative Offset … (PR #111827)

[via llvm-commits]

serge-sans-paille wrote:

@hvdijk I went from your idea, but using only two values: one to track the amount of memory available before current point, and one to track the amount of memory available after current point. It is indeed easy to reason about, as in your proposal, and behaves in a very elegant manner wrt. the combine operation.
And it passes all our examples \o/
Please let me know what you think of this.

https://github.com/llvm/llvm-project/pull/111827