[llvm] [LV] Don't treat the pointer operand of histograms as scalar uses (PR #215769)

[Graham Hunter via llvm-commits]

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@@ -2239,7 +2239,8 @@ void LoopVectorizationCostModel::collectLoopScalars(ElementCount VF) {
         return WideningDecision == CM_Scalarize;
     assert(Ptr == getLoadStorePointerOperand(MemAccess) &&
            "Ptr is neither a value or pointer operand");
-    return WideningDecision != CM_GatherScatter;
+    return WideningDecision != CM_GatherScatter &&
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huntergr-arm wrote:

What was the widening decision? It seems a little odd to have it be something other than gather/scatter for a histogram.

https://github.com/llvm/llvm-project/pull/215769