[llvm] [AMDGPU] Make max dwords of memory cluster configurable (PR #119342)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> > function attribute
> 
> Thanks! What's the suggested way to access that value in function attribute from the SIInstrInfo? Maybe keep a record of that value in MachineFunctionInfo and get from it?

That's just a matter of caching it in MFI or whether read directly from the IR attribute. In either case, the MachineFunction needs to be passed into the hook 

https://github.com/llvm/llvm-project/pull/119342