[llvm] Attributor: Add denormal-fp-math to attributor-light (PR #79576)

[Johannes Doerfert via llvm-commits]

jdoerfert wrote:

Approve and merge https://github.com/llvm/llvm-project/pull/91004, then you don't need AAIsDead and it works as expected.

https://github.com/llvm/llvm-project/pull/79576