[llvm] AMDGPU: Propagate amdgpu-max-num-workgroups attribute (PR #113018)

[Shilei Tian via llvm-commits]

shiltian wrote:

Meaning if it is done correctly, it will work as expected.

If you want to use pessimistic state as invalid, you can't touch known, because invalid state only means known to be worst. As long as known is not worst, there is no invalid state anymore, and `manifest` will always be called.

In addition, everywhere else just uses assumed, including `manifest`. To update known in `initialize` will not give you too much, unless the AA becomes pessimistic state such that known can be propagated to assume.

On the other hand, if you just update assumed, then everywhere else just gets the latest state, and `manifest` would not be called when the state is invalid (or pessimistic). This requires in `initialize` to check those values before updating assumed, because you don't want to push the state to the worst in the very beginning.

https://github.com/llvm/llvm-project/pull/113018