[llvm] [AMDGPU] Fix AAAMDWavesPerEU to union caller waves-per-eu ranges (PR #207903)

[Arseniy Obolenskiy via llvm-commits]

aobolensk wrote:

> This needs to be max on both end, because we need to take the conservative value when a function can be reached from different kernels; otherwise it would not work properly. For example, in the case used in the description, only [8,8] can make sure it can work both for [1,8] and [8,8] kernel. Using [1,8] would be broken when the [8,8] kernel reaches it.

That seems the premise of this miscompilation reports was initially incorrect. Thus, closing this PR

https://github.com/llvm/llvm-project/pull/207903