[llvm] [LV] Convert scatter stores with constant stride into strided stores (PR #206896)

[Luke Lau via llvm-commits]

================
@@ -3105,6 +3105,18 @@ static VPRecipeBase *optimizeMaskToEVL(VPValue *HeaderMask,
                                      SpliceR, EVL, Mask);
   }
 
+  if (match(&CurRecipe, m_Intrinsic<Intrinsic::experimental_vp_strided_store>(
+                            m_VPValue(StoredVal), m_VPValue(Addr),
+                            m_VPValue(Stride), m_RemoveMask(HeaderMask, Mask),
+                            m_TruncOrSelf(m_Specific(&Plan->getVF()))))) {
+    if (!Mask)
+      Mask = Plan->getTrue();
+    auto *NewStore = cast<VPWidenMemIntrinsicRecipe>(&CurRecipe)->clone();
+    NewStore->setOperand(3, Mask);
----------------
lukel97 wrote:

Nit, this is a bit shorter than the if statement
```suggestion
    NewStore->setOperand(3, Mask ? Mask : Plan->getTrue());
```

https://github.com/llvm/llvm-project/pull/206896