[llvm] [AMDGPU] Add intrinsic for raw atomic buffer loads (PR #97707)

[Matt Arsenault via llvm-commits]

================
@@ -1378,6 +1380,8 @@ std::optional<Value *> GCNTTIImpl::simplifyDemandedVectorEltsIntrinsic(
   case Intrinsic::amdgcn_raw_ptr_buffer_load:
   case Intrinsic::amdgcn_raw_buffer_load_format:
   case Intrinsic::amdgcn_raw_ptr_buffer_load_format:
+  case Intrinsic::amdgcn_raw_atomic_buffer_load:
+  case Intrinsic::amdgcn_raw_atomic_ptr_buffer_load:
----------------
arsenm wrote:

Needs instcombine tests for this. Also, would be best to do this in a separate change from the introduction of the intrinsic 

https://github.com/llvm/llvm-project/pull/97707