[llvm] [AMDGPU] Remove definition of hi16 for scalar registers (PR #197467)

[Igor Wodiany via llvm-commits]

IgWod wrote:

I have now pushed a rebased branch:

* Code is back to when @arsenm approved it + nits are addressed - hi16 is removed from all SGPR registers
* `wqm.ll` diff disappeared due to #200866 being merged

@rampitec @Sisyph Are you happy with the change? The exec bug has been addressed and nothing more shows in tests. I guess if something more surfaces we can deal with it then?

@arsenm I take you are happy with the change since it's back to when you approved it?

Again, sorry for all the confusion caused.

https://github.com/llvm/llvm-project/pull/197467