[llvm] [AMDGPU] Allow shinking instruction with dead sdst (PR #68028)

[Stanislav Mekhanoshin via llvm-commits]

rampitec wrote:

The only affected sdag test ds-combine-large-stride.ll got this instruction after SILoadStoreOptimizer when it calls TII->getAddNoCarry(). Before GFX9 it creates V_ADD_CO_U32_e64 instruction with dead sdst and no carry-in. For later targets it simply creates V_ADD_U32_e64 without carry-in and carry-out and we have no such problem.

I can just drop this patch due to low impact and interest.

https://github.com/llvm/llvm-project/pull/68028