[llvm] [AMDGPU][Attributor] Don't run `AAAddressSpace` for graphics functions (PR #108560)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> > I wouldn't bother skipping it
> 
> If we don't want to bother skipping it, do we want to do the same thing for `InferAddressSpacePass`? This can allow the TTI version of `getFlatAddressSpace` to go.

I'm pretty sure that field is just broken and should be removed. It is initialized by whatever function happens to be first when constructing the TTIImpl. The TTI is owned by the subtarget, which is unique per subtarget, not function 

https://github.com/llvm/llvm-project/pull/108560