[llvm] [CGP] Drop poison-generating flags after hoisting (PR #90382)

[Antonio Frighetto via llvm-commits]

antoniofrighetto wrote:

I just wonder if there are possibly other places in CGP where we should drop the flags, but I assume that, unless we have a test case showing that explicitly, it's fine as it is.

https://github.com/llvm/llvm-project/pull/90382