[llvm] Match fixed width ISD::AVGFLOORS + ISD::AVGCEILS patterns (PR #86222)

[Simon Pilgrim via llvm-commits]

================
@@ -3867,6 +3905,10 @@ SDValue DAGCombiner::visitSUB(SDNode *N) {
   if (SDValue V = combineFixedwidthToAVGCEILU(N, DAG))
     return V;
 
+  // Try to match AVGCEILS fixedwidth pattern
+  if (SDValue V = combineFixedwidthToAVGCEILS(N, DAG))
----------------
RKSimon wrote:

Merge this into combineFixedwidthToAVGCEILU (rename to combineFixedwidthToAVGCEIL)

https://github.com/llvm/llvm-project/pull/86222